FREE · AUTO & TRAVEL
Gear Ratio Speed Calculator.
Calculate vehicle speed in every gear at a given engine rpm from gear ratios, final drive and tyre size, and the rpm at cruising speed.
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How to use Gear Ratio Speed Calculator
Enter the tyre size, engine speed, final drive and each gear ratio.
How it works
Speed = rpm ÷ (gear × final drive) × tyre circumference × 60.
Example
Sixth gear 0.71 with a 3.94 final drive on 225/45R17 reaches 277.8 km/h at 6,500 rpm and turns 2,808 rpm at 120 km/h.
Questions about Gear Ratio Speed Calculator
Is Gear Ratio Speed Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Theoretical speeds; drag, tyre growth and slip are ignored. Everything is calculated in your browser; nothing you type is uploaded. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.