Tools

Calculators

Free motorsport engineering calculators. Built by F-tune Performance.

Tyre Size Calculator

Compare tyre dimensions, calculate rolling circumference, convert racing slick sizes and find the correct rim width. Works with standard, slick mm and slick cm formats.

Rolling circumference Slick converter Rim width Speedometer correction

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Gear Ratio & Speed Calculator

Calculate top speed and RPM per gear. Presets for ZF 8HP, Mercedes 722.6 NAG1, 7G-Tronic and 9G-Tronic. Enter your own final drive and tyre size.

Top speed RPM per gear ZF 8HP Mercedes 722.6 7G-Tronic 9G-Tronic

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HP & Torque Calculator

Convert between HP, PS, BHP and kW. Convert Nm to lb-ft. Calculate power from torque and RPM. Enter engine data for specific power, piston speed and an estimated power curve.

HP to kW Nm to lb-ft Power curve Piston speed Specific power

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