Bicycle speed depends on the ratio between the front chainring and rear cog along with your pedaling cadence. A larger chainring or smaller rear cog results in higher speed for the same cadence. Wheel diameter also plays a roleβthe larger the wheel, the farther you travel per pedal stroke.
The distance traveled for one crank revolution is the wheel circumference multiplied by the gear ratio:
where is wheel diameter, is chainring teeth, and is cog teeth. Speed is distance per minute multiplied by cadence:
To convert to kilometers per hour, multiply by 60. This calculator performs the math instantly so you can test different setups.
Enter the number of teeth on your chainring and rear cog, your wheel diameter in meters, and your expected cadence in revolutions per minute. The calculator outputs your speed in kilometers per hour. Experiment with various gear combinations to find a comfortable balance between effort and velocity for climbs, sprints, or everyday rides.
Understanding the relationship between gear ratios and speed helps cyclists train efficiently. Higher cadences may reduce muscle strain but require cardiovascular endurance, while bigger gears create more resistance. Use this tool alongside real-world rides to fine-tune your shifting strategy and push toward your fitness goals.
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