Speed Calculator

Formula

The formula to calculate the speed (S) in mph is:

\[ \text{S} = \frac{\text{G} \times \text{C} \times (\pi \times 60 / 63360)}{\text{R}} \]

Where:

\( \text{S} \) is the speed in mph
\( \text{G} \) is the gear inches
\( \text{C} \) is the cadence in rpm
\( \text{R} \) is the gear ratio
\( \pi \) is the constant Pi (approximately 3.14159)
60 is the conversion factor from minutes to hours
63360 is the conversion factor from inches to miles

What is Gear Inches?

Gear inches is a measurement used to describe the size of a bicycle’s gear. It is calculated by multiplying the diameter of the wheel (in inches) by the gear ratio. This measurement helps cyclists understand how far the bicycle will travel with each pedal revolution. A higher gear inch value indicates a harder gear, which is more suitable for high-speed riding on flat terrain, while a lower gear inch value indicates an easier gear, which is better for climbing hills.