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Cassette Calculator — Sprocket Spacing & Gear Ratios
Analyse cassette tooth counts, gear jumps, ratios and speed at cadence for road and mountain bike gearing.
Enter tooth counts separated by dashes, smallest to largest
How We Calculate This
Gear Analysis
Jump % = (Larger - Smaller) / Smaller x 100
Speed = (Chainring / Sprocket) x Cadence x Wheel circumference x 60 / 1000
Gear range = Largest sprocket / Smallest sprocket x 100%
Frequently Asked Questions
For flat terrain, 11-25 or 11-28. For hilly routes, 11-32 or 11-34. For mountains, 11-36 or wider. Wider range cassettes have bigger jumps between gears, which can feel less smooth.
Jumps under 15% feel smooth when shifting. Jumps of 15-20% are noticeable but acceptable. Jumps over 20% can disrupt your cadence significantly. Road racing cassettes (11-25) have smaller jumps than touring cassettes (11-34).
Larger wheels (700c, 29-inch) cover more ground per pedal revolution than smaller wheels (650b, 26-inch). This means a 700c wheel with the same gear ratio is effectively a slightly higher gear than a 650b wheel.
Most cyclists pedal at 80-100 RPM. Competitive road cyclists aim for 90-100 RPM. Recreational riders often sit at 70-85 RPM. Use your typical cadence for more accurate speed estimates.
Related Calculators
Gear Ratio Calculator
Calculate gear ratios from chainring and sprocket tooth counts.
Gear Inches Calculator
Convert gear ratios to gear inches for comparison.
Development Calculator
Calculate distance travelled per pedal revolution for any gear.
Speed in Gear Calculator
Calculate road speed for any gear at a given cadence.
Gear Range Calculator
Compare total gear range across different drivetrain setups.
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Last updated: March 2026
All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.