Motorcycle rear wheel horsepower calculator When you’re done, hit the drivetrain horsepower loss guestimator to run your own numbers and find out how much power your car is actually putting down. These correction factors are used by dyno shops to correct for nonstandard temperature, barometric pressure and humidity. Calculator will generate its rear wheel horsepower. 2. On the dyno what number do you typically see? My recent dyno hp is only 83. Oct 3, 2024 · Use the formula: \ ( HP = WHP \times \frac {1} {1 - DL} \), where DL is the drivetrain loss. 4 hp. This calculation is crucial for understanding the performance of your vehicle, whether it’s a Rear-Wheel Drive (RWD), Front-Wheel Drive (FWD), All-Wheel Drive (AWD), or 4-Wheel Drive (4WD). A 17% driveline loss is assumed for flywheel HP. ). If your bike made 120 hp at the crank and 100 hp at the wheel (16. Free Wheel Horsepower calculator. Jun 23, 2025 · The Wheel Horsepower Calculator allows you to determine the effective power that reaches the vehicle's wheels, considering losses in the transmission and drivetrain system. HP is at Flywheel Free Horsepower Calculator Engine Rear Wheel Horsepower Calculator Based on total vehicle weight and 1/4 mile MPH To use this horsepower calculator enter the mph trap speed at the 1/4 mile mark from one of your dragstrip ET slips. When changing sprockets, you can adjust Chain Links to maintain (nearest to) current Sprocket Centers (eg: to keep motorcycle rear wheel within adjustment range). 85), the wheel horsepower can be calculated as: This guide breaks down the difference between crank and wheel horsepower, how drivetrain loss works, and why your dyno numbers never match the spec sheet. Convert WHP to HP in seconds. Request yours to be added as well. If it's slippery it doesn't take that much horsepower. 69 = 1. How It Calculates the Results: The HP, ET, SPEED CALCULATOR This data is intended to assist our customers in understanding the relationship between vehicle HP and weight vs. Uncover the key to optimising your ride's power output. When we discuss horsepower, we’re often fascinated by the sheer figures Dec 30, 2024 · The Drivetrain Loss Calculator measures the percentage of power lost between the engine and the wheels due to friction and inefficiencies in the drivetrain. Simply input the horsepower value and select the drivetrain type then click the calculate button. For a more accurate calculation try Larry Meaux's This free calculator determines horsepower as a unit of power given force, distance, and time. 9219% Your speedo might be affected depending on where the signal comes from. Whether you ride a sportbike, cruiser, adventure bike, or scooter, choosing the right tire size can improve your ride’s safety, comfort, and performance. Change your HP and/or vehicle weight numbers and check the results. This measurement is important for assessing the actual power reaching the wheels, which differs from engine horsepower due to mechanical losses. True Rear Wheel Horsepower (tm) is Factory Pro's standard of measuring the power that is actually delivered to the rear wheel. Q: What is the wheel horsepower of a 660 bhp rear-wheel drive vehicle? A: The wheel horsepower is 539. Calculate and convert motorcycle tire sizes with our easy-to-use calculator. Jul 11, 2024 · How to Use the Drivetrain Loss Calculator: 1. Click the “Calculate” button to determine the wheel horsepower (WHP). HP = WHP * 1 / (1 – DL ) Where HP represents engine horsepower WHP is wheel horsepower DL represents drive train loss For front-wheel drive, the drive train loss is 10%; for rear-wheel drive, it is 15%; and for all-wheel drive, it is 25%. Essential for automotive enthusiasts, tuners, specialized mechanics and owners who want to know real performance. Description: Do you have a high performance car, motorcycle, truck or vehicle, built a new engine, performed a tune up or installed a performance part? Try out this calculator get a rough estimate of horsepower. 3. Estimate your drivetrain loss and calculate your engine's wheel horsepower using our simple calculator. The drivetrain loss can be used in the formula. Jul 3, 2025 · Enter your engine horsepower (HP) and wheel horsepower (WHP) to see the drivetrain loss percentage and an estimate of your drivetrain type. 089219 1. That % loss can vary based on many things, but some of the biggest variables are whether the bike is driven by chain, belt, or drive shaft. Use the “Power Measurement” Feature to estimate “Crank/Wheel Horse Power” to more accurately calculate the design of your EFI system. This calculator uses basic engine horsepower and wheel horsepower data to give you an accurate percentage of power loss in your vehicle’s drivetrain. Picking the proper fuel injector size is critical for performance and tuning control. Feb 8, 2025 · Calculate precise wheel torque for cars, motorcycles, and machinery using the Wheel Torque Calculator. Multiply brake horsepower by the assumed drivetrain efficiency (0. That’s a loss of 16%. 25 for all-wheel drive. Introduction In the automotive world, understanding the relationship between crankshaft horsepower (Crank HP) and wheel horsepower (Wheel HP) is crucial for enthusiasts, tuners, and engineers alike. Apr 25, 2025 · In the realm of automotive performance, the terms “wheel horsepower” (WHP) and “crank horsepower” (CHP) frequently arise, denoting different measurements of a vehicle’s engine output. It factors in the drivetrain loss to provide you with accurate estimations for front-wheel drive (FWD), rear-wheel drive (RWD), and all-wheel drive (AWD) vehicles. What Is Drivetrain Loss? Free online hp to whp calculator – Convert horsepower to wheel horsepower. 089219 - 1 = . . (bike is with 1500 miles, standard except Scorpion slip on. Oct 2, 2024 · The formula to calculate wheel horsepower is based on drivetrain efficiency and engine horsepower: \ [ \text {WHP} = \text {Engine Horsepower (BHP)} \times \text {Drivetrain Efficiency} \] Example Calculation For a vehicle with an engine horsepower of 300 BHP and a drivetrain efficiency of 85% (0. What are common drivetrain loss percentages? Front-Wheel Drive (FWD): 10% Rear-Wheel Drive (RWD): 15% All-Wheel Drive (AWD): 25% This calculator simplifies converting wheel horsepower to engine horsepower, helping you understand your vehicle's true Crank to Wheel Horsepower (CWHp): The horsepower effectively transferred from the engine to the wheels of the vehicle, taking into account power loss. Not a substitude for actual testing. Formula The formula below is used to calculate engine horsepower (hp) from wheel horsepower (WHP). 67% loss), then you should expect that it makes 132 bhp at the crank if it makes 110 hp at the wheel. For front-wheel drive, the drive train loss is 10%, for rear-wheel drive, it is 15%, and for all-wheel drive, it is 25%. Any truth to this or is there a different formula? Oct 3, 2024 · Example Calculation For an engine producing 500 HP, with 400 HP measured at the wheels: \ [ DL = \frac {500 - 400} {500} \times 100 = 20\% \] This indicates a 20% loss in power through the drivetrain, which might suggest an all-wheel-drive system, where losses are typically higher than in two-wheel-drive configurations. co. All FuelTech engine management systems are capable of driving stock injectors to massive 850 lb/hr injectors. Every vehicle experiences some form of power loss between the engine (where the power is generated) and the wheels (where the power is utilized for movement). Jun 9, 2023 · The Crank to Wheel HP calculator is a simple yet practical tool that estimates the horsepower at the wheels from the crankshaft horsepower. Sep 10, 2025 · To calculate the HP from WHP, multiply the wheel horsepower by 1 divided by the result of 1 minus the drive train loss. 15 for rear-wheel drive, and . 8173). Use our WHP to HP Calculator to easily convert Wheel Horsepower (WHP) to Horsepower (HP). The big end is where it's at! Drag Performance Calculator By AssassinRacing. Oct 1, 2014 · Also how I can calculate actual hp figure as to compare it manufacturers calculations, I do believe that Kawasaki measuring crankshaft hp and not rear weel. Convert engine horsepower to wheel horsepower based on drivetrain type. When you choose horsepower, this calculator will measure the approximate horsepower of an engine based on the torque of the engine (measured in foot-pounds) multiplied by the RPM of the engine, divided by 5,252 (conversion between foot-pounds and horsepower). 85, and you get the crank horsepower. WHP to HP Calculator The calculator will convert wheel horsepower (WHP) to engine horsepower (EHP) and vice versa, based on the drivetrain loss percentage, and show detailed calculations. Jan 14, 2012 · How to calculate RWHP vs Crank HP There is no magic formula, because there are just too many variables. Mar 27, 2025 · Want to convert WHP to HP easily? Our WHP to HP Calculator helps you estimate your vehicle’s crank horsepower based on wheel horsepower and drivetrain type. Multiply that by 100 to get the percentage. It is the actual power being put down to the ground. Compare different tire sizes and find compatible options for your motorcycle. 9% of the claimed number. For example, BMW claims 199 at the engine, and bikes will get around 175 to 185 at the wheels, depending on dyno. For example, a tire size of 120/70-17 can be broken down as follows: Aug 10, 2011 · I have noticed that manufacturers claim 50 brake horsepower [bhp]output and that is something very different from wheel hp. 15 = 690 If you want 600 wheel horsepower you need a turbo that can support 690 crank horsepower. Which seems very unreasonable when most accepted number is around 10%. This guide will make understanding motorcycle tire sizes easy. [whp] Since I got whp readings I am curious to know the approximate drivetrain losses in percentage to calculate how much whp would a 50 bhp bone stock machine make. Jan 9, 2024 · The rwhp to hp Calculator is a valuable tool used to convert rear-wheel horsepower (rwhp) into regular horsepower (hp). 089219 . Try now! Apr 2, 2009 · Motorcycle performance data tested by the Motorcyclist Magazine staff using a Dynojet dynomometer and manufacturer data. It is honest, true, fair and duplicable. Our WHP to HP Calculator is a simple and efficient tool designed to help you calculate the engine’s horsepower based on WHP and drivetrain type in just a few clicks. While WHP represents the power reaching the wheels, HP accounts for drivetrain losses, providing a more accurate picture of an engine’s full capacity. The Wheel Horsepower Calculator is a useful tool for calculating your car's wheel horsepower based on factors such as engine power, gear ratio, tire size, drive train type, and the number of driven wheels. 4. Estimate Your Horsepower! *Note: Assuming a 20% drive train loss. In this article, we will delve Nov 16, 2025 · Motorcycle speed and sprocket calculator with bike database for gearing, sprockets, tires and chains of over 1900 bikes. Oct 1, 2025 · Enter the Brake Horsepower and percentage of power loss into the calculator to determine the Crank to Wheel Horsepower. Importance and Usage The WHP to HP calculator converts the wheel horsepower (WHP) to crank horsepower (HP) and vice versa. FuelTech offers a Fuel Injector Calculator to assist racers and builders select the proper fuel injector sizing. Whether you're evaluating vehicle specifications, comparing motor outputs, or designing mechanical systems, our calculator delivers instant horsepower conversions and calculations without complex equations. This tool accounts for power losses that occur through drivetrain components, providing accurate performance metrics for vehicles. Usually, you will see a 15% loss from crank hp to rwhp on a manual 3 days ago · Estimate Horsepower from Head AirflowBack to Calculators Index These equations are for recreation only. Then enter the total weight of your vehicle, as raced, including the drivers weight. Enter the engine power of your vehicle in horsepower (HP). What is Horsepower Calculator At Horsepower Calculator, we provide accurate and intuitive tools to measure engine power and performance. This calculator estimates your 60 foot, eighth and quarter mile elapsed times and trap speed when given the weight of the car and flywheel or wheel horsepower. uk to aid you in configuring your vehicle to get the most out of it. Rear-wheel horsepower (rwhp) is measured on a dynamometer most likely at your favorite tuner's shop. Jan 18, 2024 · FAQs How do you convert HP to WHP? To go from horsepower to wheel horsepower, you’ll need a calculator to know how your car’s drivetrain works. Free online horsepower calculator with multiple methods to determine engine power - torque and RPM, 0-60 time, or wheel horsepower from dyno testing. Drag Racing Calculators,Calculators to find 1/4 mile ET and MPH, CID,Piston Speed,gear ratio,carburetor size,margin of victory,Engine calculator, Calculates relative horsepower, air density, density altitude, virtual temperature, actual air pressure, vapor pressure and dyno correction factor and more. 1/4 mile speed and ET. Information about motorcycle horsepower, torque, acceleration, and speed. Are there any experienced guys here who have done lots of dyno runs in various 1/4 Mile MPH Calculator by RPM, Tire Height, Rearend Ratio, Trans Ratio, & Converter Slip The standard formula for converting WHP to HP is: HP = WHP / Drivetrain Efficiency. Power Loss Percentage (L): The percentage of power loss due to factors such as friction, heat, and other mechanical inefficiencies. Check Lock Centers and adjust sprockets - Chain links will adjust to maintain nearest to Using information such as tire size, gear ratios, horsepower, and displacement, this handy slide tool works out the relationship between: Use our free online Horsepower Calculator to estimate engine power using torque and RPM. This distinction is valuable in automotive tuning and performance assessment, especially for comparing engine power 1/4 ET/SPEED/HP/KW Calculator Weight is as the car sits on the line: driver and gas in it. 4 days ago · Fuel Injector Size Calculator Back to Calculators Index These equations are for recreation only. That way I can compare the results! Mar 25, 2021 · Rear wheel horsepower and torque measured on a dyno accurately portrays what a motorcycle is actually putting to the ground. Your primary drive, transmission and rear drive sprockets all combine to determine your cruising rpm as well as your final top speed. That's the increase in driveline torque at the rear wheel. WHP or wheel horsepower is the measure of the horsepower being delivered to the wheels on a chassis dyno. Fast, simple, and accurate. MPH Calculator / Horsepower Calculator / ET Calculator / RPM Calculator Input the Weight and 1/4 mile Trap speed of your vehicle. Whether you’re working with wheel HP for drag racing calculations or simply curious about power output, this calculator is a must-have for precise tuning and performance analysis. Select your vehicle’s drivetrain type from the dropdown (Front-Wheel Drive, Rear-Wheel Drive, or All-Wheel Drive). 93 / 2. *Note: Assuming a 20% drive train loss. The lower the chain revolutions, the more frequently each chain link engages the same sprocket tooth, so greater and more uneven the wear. Testing from the crank is completely pointless anyways, because of drivetrain losses, thats why rear wheel horsepower is what dynos test for anyways. The tachometer will not. If you want to test crank horsepower, you have to attach the engine to a dyno that tests from the crank. The “Crank to Wheel HP Calculator” emerges as a valuable tool in this context, providing a means to estimate the power loss between the engine and the wheels. Wheel torque can be calculated function of engine torque if the parameters and status of the transmission are known. TCI Auto offers you an array of Automotive Racing Calculators allowing you to figure out displacement, Horsepower, Quarter Mile Times, and more! Our handy motorcycle tire size calculator helps riders compare tire sizes including tire’s width, aspect ratio, construction type, and rim diameter. You'll learn how to figure out the dimensions and pick the best tires for your bike, whether Calculate wheel horsepower (WHP) to horsepower (HP) online. Apr 28, 2018 · Explore motorcycle horsepower performance with a focus on "effective horsepower" measured at the wheel. Simply enter your Wheel Horsepower (WHP), select your drivetrain type, and get the HP conversion instantly! Dec 5, 2024 · The WHP to HP Calculator helping in converting wheel horsepower to crank horsepower, offering a complete view of engine output. The engine’s power output is typically higher than the power delivered to the wheels due to drivetrain power losses. * Enter Parameters Below * Motor Speed RPM (example: 8000) * Motor Sprocket Teeth (example: 10) * Wheel Sprocket Teeth (example: 36) * Tire Diameter Inches (example: 26) Speed and Gear Ratio Calculation Results Top Speed: MPH Gear Ratio: :1 Rollout 75% Speed Convert WHP to HP. Determine the horsepower delivered to the wheels from the engine with our wheel horsepower calculator. Selecting the proper size injector Sep 11, 2025 · Enter the engine torque and select the type of drive-train into the calculator to determine the wheel torque. Brake Horsepower vs Wheel Horsepower BHP or brake horsepower is the measure of horsepower at the flywheel of the engine when the engine is not installed in the vehicle. What is crank horsepower? Drag Performance CalculatorDRAG PERFORMANCE CALCULATOR HP measured at the engine is always much higher then whats at the rear wheel. This conversion is particularly helpful for automotive enthusiasts, mechanics, and anyone dealing with vehicle performance metrics. Whether you’re comparing dyno results or planning performance upgrades, accurately converting Wheel Horsepower (WHP) to Engine Horsepower (HP) is essential. What is a typical drivetrain loss percentage on the dyno? Let’s say a bike claimed hp is 100hp. This calculator converts your dyno run into corrected SAE, MSA and STD horsepower. This program will give you an estimate of the horsepower produced by your bike if you know the weight of the bike, a quarter mile ET (elapsed time) and the quarter mile speed in miles per hour. This conversion utility was jointly developed between FrozenMist and www. When I show up on a new motorcycle, the two things folks usually ask me are The Colorado Sportbike Club Speed Calculator Determine your motorcycle's speed in a specific gear at a certain RPM Thinking about changing your sprocket gearing but wondering how it's going to affect your top-end? Or, do you want to know your bikes top-speed without breaking the law? This page can help! To use this calculator, you will need the Primary Reduction Ratio, Final Reduction Ratio This free engine horsepower calculator estimates vehicle engine horsepower using two different methods: the elapsed time method and the trap-speed method. Engine horsepower (HP) represents the raw power generated by the engine, wheel horsepower (WHP) indicates the usable power that reaches the wheels after accounting Nov 5, 2024 · Motorcycle enthusiasts and car tuners can utilize the rear wheel horsepower calculator or wheel HP to crank HP calculator to optimize performance. Even 15% is a stretch. May 31, 2020 · The higher the torque at the rear wheel, the faster you can accelerate (theoretically as at some point the wheel will start slipping of course) but you’ll reach the engine’s max RPM quicker, so your motorcycle’s top speed would be lower (leaving gears out of the discussion for simplicity). This calculator will show you your speed in each gear from everything from a stock bike to an all out drag bike with a separate jackshaft as well as the one we love the most, the Bonneville racer. In order to find a turbo that can support our target power we need to calculate for the drivetrain loss and multiply 600 x 1. It is an essential tool for automotive enthusiasts, mechanics, and engineers who need to understand the performance output of a vehicle’s engine and its transmission to the wheels. Also provided is a converter for common units of power. This calculator is based on Naturally Aspirated applications. This calculator computes the estimated engine or motor horsepower from trap speed. Simply enter your WHP and tire size to accurately determine the horsepower of your vehicle. com Calculate the theoretical 1/8 Mile ET, 1/4 Mile ET, 1/4 Mile Top End Speed, and Ideal 1/4 Mile Gear Ratio for a given application based on the Vehicle Weight (in pounds), Vehicle Horsepower (at the flywheel), RPM through lights (finish line), and Tire Diameter (Height) in Inches. Feb 8, 2025 · The WHP (Wheel Horsepower) to HP (Horsepower) Calculator is a useful tool which is designed to convert wheel horsepower (measured at the wheels) into crank horsepower (measured at the engine’s crankshaft). Does HP stand for horsepower? Yes, in the field of auto mechanics, HP stands Sep 11, 2025 · Enter the engine horsepower and select the drive system to determine a car's wheel horsepower. It is the ONLY standard that can be duplicated by the entire industry - regardless of the dyno manufacturer. Enter the weight of your vehicle in pounds (lbs). Accurate calculations for front-wheel, rear-wheel, and all-wheel drive systems. This calculator can also evaluate any of the variables given the others are known. 089219 x 100 = 8. Understanding this distinction is critical for us as vehicle enthusiasts, tuners, or anyone involved in the automotive industry. The Motorcycle Tire Size Calculator is your go-to tool for safely upgrading, replacing, or experimenting with new tire sizes. In this tutorial, we are going to calculate the wheel torque and force for a given: engine torque gear ratio (of the engaged gear) final drive ratio (at the differential) (free static) wheel radius Also, we are going to assume that there is no slip in the clutch or torque This easy online sprocket calculator will help you determine the effect that different sprockets will have on your motorbike and help you calculate the best sprocket sizes for your riding style. mk5cortinaestate. Sep 3, 2024 · Motorcycle Tire Size Calculator Tire Width (mm): Aspect Ratio (%): Rim Diameter (inches): Calculate Getting the right tires for your motorcycle is key for its performance, handling, and safety. Great for cars, bikes, and tuning. Calculates precise values for front-wheel, rear-wheel, all-wheel and 4-wheel drive, offering detailed Doctor Moto - Dynamometers & Horsepower Everybody who's into motorcycles talks about horsepower at one time or another. Its difficult to show crank horse power from a dyno because a dyno cannot properly assume all things that cause power train loss. Free online whp to hp calculator – Convert wheel horsepower to horsepower. Mar 1, 2025 · A WHP to HP Calculator is a tool used to estimate a vehicle’s engine horsepower (HP) based on its wheel horsepower (WHP) and drivetrain type. Enter wheel horsepower and drivetrain loss to get true engine horsepower for FWD, RWD, or AWD. The drive train loss is . Brake Horsepower (BHp): The total horsepower before power loss. By understanding WHP, car enthusiasts, racers, and engineers can better gauge vehicle performance and make informed Formula To calculate the Engine Horsepower (HP) and Brake Horsepower (BHP) from Wheel Horsepower (WHP): This calculator estimates your quarter mile elapsed time (ET) when given the weight of the car and flywheel or wheel horsepower. Jan 22, 2008 · Does anyone know the calculation on how to convert wheel horsepower to crank horsepower? I read that you have to take the WHP and divide it by 0. Divide your new ratio by your old one, and subtract 1 from the answer. Some include gearing, condition of lubricants, mass of rotating parts, manual or automatic transmission and a few others. Simply input your wheel horsepower value and select drivetrain type then click the calculate button. It is impossible to calculate these values accuratly, this information should be used as a rough guide only. Essential for understanding vehicle performance and drivetrain efficiency. Nov 22, 2024 · The Wheel Horsepower Calculator can convert engine horsepower to wheel horsepower, accounting for power lost through the drivetrain. The Built Bottom End Performance horsepower calculator will calculate your engine's wheel (whp) and crank (chp) horsepower using proven mathematical functions based on real-world examples. This hp to whp calculator use WHP = Engine HP × (1 – (Drivetrain Loss / 100)) formula to measure the actual power output delivered to the wheels of a vehicle. 10 (10%) for front-wheel drive, . The HP is based on flywheel HP, for rear wheel HP multiply the results by your drive train percentage loss and subtract it from the result. Apr 30, 2020 · For this example we are going to start with a wheel horsepower target of 600 for a rear wheel drive application. 300 mph rated Goodyear rubber, no prominent tail fin, rear wheel positioned for the long wheelbase and no long tail overhang. ipydrgjinehikqqwamwbztpxpgyxrrysajfxpkwnfpdgvtpakhjobeotkqhqubcuwgejlplfczvyrrsuhuhehe