Bike Cadence and Speed Calculator

Convert between cycling cadence (RPM), speed, and gear ratio. Find the balance of pedaling rate and velocity for any terrain.

About the Bike Cadence and Speed Calculator

The relationship between cadence and speed is one of the most basic cycling calculations. Speed depends on how fast you pedal, what gear you choose, and how large your wheels are.

This calculator works in both directions — enter a target speed to find the required cadence, or enter a cadence to see what speed you can expect. It accounts for wheel size and drivetrain gearing so you can compare setups without treating any one number as a universal target.

Use the output as a planning aid for route selection, gear choice, and training comparisons.

Why Use This Bike Cadence and Speed Calculator?

This calculator helps you compare cadence, speed, and gearing in a single place. It is useful for route planning, drivetrain setup, and checking whether a chosen gear range matches the terrain you ride.

How to Use This Calculator

  1. Choose your calculation mode: Speed from Cadence or Cadence from Speed.
  2. Enter your cadence (RPM) or target speed depending on mode.
  3. Select your front chainring and rear cog tooth counts.
  4. Choose your wheel size from common presets or enter custom circumference.
  5. View computed speed or required cadence plus related metrics.
  6. Compare results across multiple gear combinations in the table.
  7. Use presets to quickly check common riding scenarios.

Formula

Speed (km/h) = Cadence × Gear Ratio × Wheel Circumference × 60 / 1000. Cadence (RPM) = Speed (km/h) × 1000 / (Gear Ratio × Wheel Circumference × 60). Where Gear Ratio = Front Teeth / Rear Teeth.

Example Calculation

Result: 39.4 km/h (24.5 mph)

With a 52/15 gear ratio (3.47) on 700×25c wheels (2.105m circumference), pedaling at 90 RPM produces a speed of about 39.4 km/h. That is a fast road-riding tempo and would usually require a strong steady effort.

Tips & Best Practices

Understanding the Cadence-Speed-Gear Triangle

Every cycling speed is the product of cadence and gear development (gear ratio × wheel circumference). This means there are many cadence-gear combinations that can produce the same speed.

Practical Applications

Road riders use cadence-speed knowledge to select gearing for time trials and steady rides. Triathletes use it to check whether their race-pace targets are realistic. Mountain bikers and commuters can use it to confirm that their easiest gear is low enough for the steepest terrain they ride.

Using the Number

Treat the result as a comparison number for route and gear planning rather than as a judgment of riding quality or fitness.

Sources & Methodology

Last updated:

Methodology

The calculator applies bicycle kinematics to convert between cadence, gear ratio, wheel circumference, and speed. It is a planning worksheet for riding conditions, not a performance score or a prescriptive target.

Sources

Frequently Asked Questions

What cadence do I need for 30 km/h on a road bike?

It depends on gearing. In a 50/17 gear (2.94 ratio) on 700×25c wheels, you would need about 80 RPM. In a 39/17 gear, you would need a higher cadence.

How does tire pressure affect the calculation?

Tire pressure slightly changes the effective rolling circumference — lower pressure creates more tire deformation. The difference is usually small enough that standard circumference values remain useful.

Is higher cadence always better for speed?

Not necessarily. Higher cadence at the same gear means more speed, but it also increases cardiovascular demand. The best balance depends on fitness and terrain.

What cadence do Tour de France riders use?

Many riders pedal at roughly 90-100 RPM on flat stages, with a wider range on climbs and in sprints. Individual preferences vary.

How do I calculate cadence without a sensor?

Count your pedal strokes for 15 seconds and multiply by 4, or use this calculator in reverse by entering your known speed and gearing.

Does cadence change with fatigue?

Yes. Cadence often drifts downward on long rides as neuromuscular fatigue accumulates, which is why cadence drills can be useful.

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