🚴 Bike Cadence & Speed Calculator
Enter cadence, gearing, and wheel circumference to estimate cycling speed and rollout per pedal stroke.
700×25c tyres are ~2100 mm, 29er MTB tyres ~2300 mm. Measure a full wheel rotation for accuracy.
Gear Ratio
3.25 : 1
Chainring to sprocket teeth ratio
Speed
36.9 km/h
(36.9 km/h • 22.9 mph)
Rollout per Pedal Stroke
6.83 m
Move this far down the road each full revolution
How to Use This Calculator
Measure wheel circumference
Roll the wheel one revolution on the ground and measure distance in millimetres.
Enter cadence
Use your target cadence from training or races (e.g., 90 rpm).
Set gearing
Input chainring and sprocket teeth for the gear you plan to use.
Review speed & rollout
Use the results to choose the right cassette or adjust cadence goals.
Formula
Speed (km/h) = Cadence × Gear Ratio × Wheel Circumference × 60 ÷ 1,000,000
Wheel circumference must be in millimetres. Gear ratio equals chainring teeth divided by sprocket teeth. Multiply cadence (rpm) by gear ratio and wheel circumference to get distance per minute, then convert to km/h or mph.
Example
52/16 gear, 2100 mm wheel, cadence 95 rpm → Speed ≈ 95 × (52/16) × 2100 × 60 ÷ 1,000,000 = 38.8 km/h.
Variables
- Cadence: Revolutions per minute
- Gear ratio: Chainring ÷ sprocket
- Wheel circumference: Tyre rollout distance
Understanding Gear & Cadence
Cadence drills and gear selection play huge roles in cycling efficiency. Choose ratios that keep cadence within your aerobic sweet spot while delivering desired speed.
Coaching Tips
- Sprinters train high cadence (110+ rpm) to build neuromuscular snap.
- Time trialists choose big gears to balance cadence ~90 rpm and aerodynamic power output.
- Climbers often gear down to maintain cadence on steep gradients.
Practical Uses
- Plan cassette ratios for mountainous vs flat routes.
- Determine target cadence for smart trainer workouts.
- Estimate speed changes when swapping from compact to standard chainrings.
Frequently Asked Questions
How do I measure wheel circumference?
Mark the tyre valve, roll one full revolution, and measure the ground distance or use manufacturer charts.
What cadence should I target?
Most riders perform efficiently between 85–95 rpm on flat terrain; experiment to find your sweet spot.
Does tyre width affect speed?
Yes, wider tyres slightly increase circumference, raising speed at identical cadence and gearing.
Can I use this for fixed gear bikes?
Definitely—fixed gear riders rely on cadence gearing relationships to plan urban or track efforts.
What about double chainring bikes?
Run the calculator for each chainring/sprocket combo to build a table of speeds at specific cadences.