Bike Cadence and Speed Calculator

Find speed from cadence and gearing.

Cadence (RPM)

Chainring teeth

Rear cog teeth

Wheel circumference

Speed 40.5

Speed 25.166

Formula: speed = cadence × (chainring/cog) × circumference × 60 ÷ 1000

Step-by-step with your numbers:

1. Values used:

2. Cadence = 90 RPM

3. Chainring teeth = 50

4. Rear cog teeth = 14

5. Wheel circumference = 2.1

7. Speed = 40.5

8. Speed = 25.166

Did we solve your problem today?

Find how fast you'll go at a given pedaling cadence and gear.

The math behind it

speed = cadence × gear ratio × wheel circumference × 60 ÷ 1000 (km/h).

90 RPM, 50/14, 2.1 m → ~40.5 km/h.

Ideal cadence?

Many cyclists target 80–100 RPM.