Bike Cadence and Speed Calculator
Bidirectional bike cadence & speed calculator. Enter wheel size, tire thickness, chainring, and cog to instantly convert speed to cadence or cadence to speed.
About This Calculator
The Bike Cadence and Speed Calculator helps cyclists convert between pedaling cadence (RPM) and riding speed (km/h and mph) based on their bike's gear setup and wheel dimensions. Whether you know your cadence from a sensor and want to estimate speed, or you know your speed from a GPS device and want to find your cadence, this bidirectional calculator handles both directions instantly.
The calculator uses the fundamental relationship between cadence and speed: Speed = π × (wheel diameter + 2 × tire thickness) × gear ratio × cadence, with appropriate unit conversions. The gear ratio is calculated as chainring teeth divided by cog teeth. For the reverse calculation, cadence = speed / (π × (wheel diameter + 2 × tire thickness) × gear ratio). First, the wheel circumference is computed from the wheel diameter and tire thickness. Then, the gear ratio converts wheel RPM to crankset cadence or vice versa. The calculator also displays a cadence-vs-speed curve showing how speed changes across cadences from 40 to 120 RPM with the current gear setup, helping cyclists optimize their gearing for target speeds or cadences.
Regional Notes
India (IN): Indian cyclists commonly use 26-inch or 29-inch wheel mountain bikes and road bikes with compact cranksets (34-50T chainrings, 11-34T cassettes). Typical commuting speeds range from 15-25 km/h with cadences around 60-80 RPM. This calculator uses metric speed units (km/h) as standard.
United States (US): US cyclists often measure speed in miles per hour. The calculator provides both km/h input and mph output. Common setups include 700c road wheels (~27-inch diameter) with standard 53/39T chainrings and 11-28T cassettes. Recreational cycling speeds average 16-24 km/h (10-15 mph).
United Kingdom (UK): UK cyclists use metric speeds and imperial wheel sizes. Popular configurations include 700c wheels with compact or semi-compact cranksets. Average club riding speeds of 24-28 km/h typically correspond to cadences of 75-90 RPM with appropriate gearing. The calculator supports both input directions for versatile use.
Frequently Asked Questions
What is bike cadence and how is it related to speed?
Bike cadence is the rate at which a cyclist pedals, measured in revolutions per minute (RPM) of the crankset. Cadence and speed are directly related through the gear ratio and wheel size. A higher cadence at the same gear ratio results in higher speed, while a lower cadence produces lower speed. The relationship is: Speed = π × (wheel diameter + 2×tire thickness) × (chainring/cog) × cadence, with appropriate unit conversions.
How do I use the bike cadence and speed calculator?
To use this calculator, enter your wheel diameter in inches, tire thickness in inches, chainring teeth count, and cog teeth count. Then enter either your speed in km/h to calculate cadence, or your cadence in RPM to calculate speed. The calculator automatically computes the missing value along with gear ratio, wheel circumference, and displays a cadence-vs-speed curve chart for reference.
What is the formula for calculating bike speed from cadence?
The formula to calculate bike speed from cadence is: Speed (km/h) = π × (wheel diameter + 2 × tire thickness) × 0.0254 × (chainring teeth / cog teeth) × cadence (RPM) × 60 / 1000. This formula converts the wheel circumference from inches to meters, multiplies by the gear ratio and cadence, then converts the result from meters per minute to kilometers per hour.
What is the formula for calculating bike cadence from speed?
The formula to calculate bike cadence from speed is: Cadence (RPM) = Speed (km/h) × 1000 / 60 / (π × (wheel diameter + 2 × tire thickness) × 0.0254) / (chainring teeth / cog teeth). This converts speed to meters per minute, divides by the wheel circumference to get wheel RPM, then divides by the gear ratio to find crankset cadence.
What is the ideal cadence range for cycling?
For recreational cyclists, the ideal cadence range is 60-80 RPM. More experienced cyclists and racers typically maintain 80-100 RPM for optimal efficiency. Track cyclists may spin at 120+ RPM during sprints. The best cadence depends on your fitness level, terrain, and personal comfort. This calculator lets you explore how different cadences translate to speed with your specific gear setup.
How does gear ratio affect speed and cadence?
Gear ratio (chainring teeth divided by cog teeth) directly determines how much speed you get from each pedal stroke. A higher gear ratio (larger chainring or smaller cog) means each pedal revolution moves the bike further, giving higher speed at the same cadence. A lower gear ratio (smaller chainring or larger cog) means less distance per revolution, requiring higher cadence to maintain the same speed.
How does wheel size affect bike speed and cadence?
Larger wheels cover more distance per revolution, so for the same cadence and gear ratio, larger wheels result in higher speed. Common wheel sizes include 26-inch (mountain bikes), 27.5-inch (trail bikes), 29-inch (modern mountain bikes), and 700c (road bikes, approximately 27 inches). Tire thickness also adds to the effective diameter, increasing the wheel circumference and thus speed.
Can I use this calculator for any bicycle type?
Yes, this calculator works for any bicycle type including road bikes, mountain bikes, hybrid bikes, touring bikes, cyclocross bikes, and e-bikes. Simply enter your specific wheel diameter, tire thickness, chainring teeth, and cog teeth values. For e-bikes with pedal assist, enter your actual riding speed or mechanical cadence to see the corresponding value.