Cycling Power Calculator

Calculate cycling power output based on speed, weight, grade, and conditions. Estimate watts and power-to-weight ratio.

Inputs

Total Weight (Rider + Bike)

Speed

km/h

Grade

Wind Speed

km/h

Tab to move between fields

Results

Total Power

174.48 W

≈ 17 LED bulbs

Watts per kg

2.18 W/kg

Rolling Resistance32.7 W

Air Resistance141.78 W

Climbing Power0 W

How to Use This Calculator

Enter your Total Weight (rider plus bike) in kilograms.
Set your Speed, Grade (hill gradient %), and Wind Speed.
Review the Total Power output in watts and the breakdown by aerodynamic drag, rolling resistance, and climbing.
Use the Watts per Kilogram (W/kg) value to benchmark your power-to-weight ratio.

How the result changes with Speed

Speed	Total Power	Watts per kg
12	22.15 W	0.28 W/kg
42	434.83 W	5.44 W/kg
78	2,576.99 W	32.21 W/kg
108	6,732.72 W	84.16 W/kg

What each input means

Total Weight (Rider + Bike): Combined weight of cyclist and bicycle
Speed: Cycling speed
Grade: Road gradient percentage (positive = uphill)
Wind Speed: Wind speed (optional)

How this is calculated

Formula

Power = Rolling Resistance + Air Resistance + Climbing Power

Worked example, using the default values

Identify Input Parameters
4 parameters
Total Weight (Rider + Bike) = 80, Speed = 30, Grade = 0, Wind Speed = 0 = 4 input(s) provided
Calculate Total Power
Total Power
174.48240740740744 = 174.48240740740744
Calculate Watts per kg
Watts per kg
2.181030092592593 = 2.181030092592593
Calculate Rolling Resistance
Rolling Resistance
32.7 = 32.7
Calculate Air Resistance
Air Resistance
141.78240740740745 = 141.78240740740745

Engine last updated August 6, 2026. Checked against 1 independently-derived test — how we verify calculators.

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