Bike Gear Calculator
Compare gear ratios and check the range a drivetrain provides.
About Bike Gear Calculator
Gear range determines the span of gradients and speeds a bike handles. A range around 400 per cent covers steep climbs and fast descents, while narrower ranges give closer spacing between gears. Range and spacing trade against each other with a fixed number of gears, which is the central design compromise in any drivetrain.
Formula
Bike Gear
Gear range = highest ratio ÷ lowest ratio, expressed as a percentage
- gear range
- The span between the easiest and hardest gear
- development
- Metres travelled per pedal revolution in that gear
Worked example
With the default values below, Bike Gear Calculator returns Gear Range of 454.5%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Largest chainring teethaccepts 20–70
- 50
- Smallest chainring teethaccepts 20–70
- 34
- Largest sprocket teethaccepts 8–52
- 34
- Smallest sprocket teethaccepts 8–52
- 11
- Wheel circumferenceaccepts 500–3,000 mm
- 2,105 mm
Results
- Gear Range
- 454.5%
- Highest Gear Ratio
- 4.5455
- Lowest Gear Ratio
- 1.0000
- Development in the Highest Gear
- 9.5682 m
- Development in the Lowest Gear
- 2.1050 m
Step by step
- 1Values used
- 2Bike Gear
- 3Gear Range= 454.5
- 4Highest Gear Ratio= 4.5455
- 5Lowest Gear Ratio= 1.0000
- 6Development in the Highest Gear= 9.5682 m
- 7Development in the Lowest Gear= 2.1050 m
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
Frequently Asked Questions
How is Bike Gear calculated?
Gear range = highest ratio ÷ lowest ratio, expressed as a percentage Gear range determines the span of gradients and speeds a bike handles. A range around 400 per cent covers steep climbs and fast descents, while narrower ranges give closer spacing between gears.
Why does Bike Gear matter?
Range and spacing trade against each other with a fixed number of gears, which is the central design compromise in any drivetrain.
What values do I need to enter?
This calculator takes 5 inputs: Largest chainring teeth, Smallest chainring teeth, Largest sprocket teeth, Smallest sprocket teeth, Wheel circumference. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.