Skip to content
OneKitly
Sign up · Sign in

Cycling power calculator

Estimate the power (watts) needed to ride at a speed on the flat.

Related tools

All Running & endurance tools →
Cycling Power Zones CalculatorGet your Coggan cycling power zones (Z1–Z5) from your FTP.FTP calculator (cycling)Estimate your cycling Functional Threshold Power from a 20-minute test.Cycling speed calculatorTurn a distance and a ride time into your average speed — in km/h and mph — and the pace per kilometre. Handy for pacing a sportive or checking a training ride.Power-to-weight ratio calculatorCompute your cycling power-to-weight ratio in watts per kilogram.Boxing punch power calculatorImpact force is the effective striking mass times the change in speed over the contact time (F = m·v/t); the punch also carries momentum m·v and kinetic energy ½·m·v². Enter the mass behind the fist, the fist speed and the contact time.Pace CalculatorCompute your running pace (min/km) and average speed from distance and time.Sprint speed calculatorCompute your speed in m/s, km/h and mph from a sprint distance and time.Swimming pace calculatorCompute your swimming pace per 100 m and speed from a distance and time.

The Cycling power calculator turns Speed (km/h), Rider + bike weight (kg) into Power, instantly and for free. For instance, with Speed (km/h) = 30 and Rider + bike weight (kg) = 80 it returns Power = 146 W.

How to use it

  1. Enter your values: Speed (km/h), Rider + bike weight (kg).
  2. Read the result instantly: Power.

Frequently asked questions

How does the Cycling power calculator work?

It takes Speed (km/h) and Rider + bike weight (kg) and derives Power from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

2 values: Speed (km/h) and Rider + bike weight (kg). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Speed (km/h) = 30 and Rider + bike weight (kg) = 80, the calculator returns Power = 146 W. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Speed (km/h) = 33 and Rider + bike weight (kg) = 88 instead, Power goes from 146 W to 191 W — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Speed (km/h) = 27 and Rider + bike weight (kg) = 72, Power comes out at 109 W. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Preparing a race: the pace a target time needs, the splits to hold it, and the training zones that sit under it — on foot, and equally on a bike or in a pool, where the same session is measured in watts or in a hundred-metre split instead.

What is the most common mistake?

Scaling a time linearly to a longer distance. A marathon is not two half-marathons; race predictors use an exponent around 1.06 precisely because fatigue is not proportional.

How accurate is it, and what are the limits?

Flat-road estimate.

What is the difference between the Cycling power calculator and the Cycling Power Zones Calculator?

This one returns Power; the Cycling Power Zones Calculator returns Zone 1 max — Active recovery (W) and Zone 2 max — Endurance (W). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

FTP calculator (cycling) is the closest one after this: Estimate your cycling Functional Threshold Power from a 20-minute test.

Further reading

All guides →
ExplainerCycling Power (Watts) ExplainedPower is the objective measure of cycling effort. Here's what watts mean, why they beat speed and heart rate, what FTP is, and why watts per kilo matter.How-toHow to Calculate Cycling Power Zones From Your FTPTurn your FTP into the seven Coggan training zones, each a percentage of threshold power, to guide every ride.ExplainerWhat Is Cycling FTP (Functional Threshold Power)?FTP is the highest power in watts you can hold for about an hour. Learn how to test it, why watts per kilogram matters, and how it guides training zones.ExplainerPower-to-Weight Ratio Explained (W/kg in Cycling)Watts per kilogram is the number that decides who climbs fastest. Learn how W/kg works, what it means for FTP and how to improve it.ExplainerCycling Speed Is Mostly a Fight With AirRolling resistance grows with speed, air resistance grows with its square, and power grows with its cube. Work the equation and the crossover falls at 10 mph — after which almost everything you pay for is air, and a headwind costs more than the same tailwind returns.ExplainerVO2 Max Norms by Age: What Your Number MeansWhat VO2max measures, how it ranges by age and sex in ml/kg/min, and the training that raises it.