Automotive calculators • Free
Real numbers for real builds.
Fast, no-nonsense calculators for drivers, builders and garage tinkerers. Compare tire sizes, check wheel fitment, estimate fuel cost, calculate power-to-weight and connect RPM to road speed.
Garage tools
No account. No spreadsheet archaeology. Just enter the numbers and get the answer.
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Tire Size Calculator
Compare diameter, circumference, ride-height change and speedometer error.
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Wheel Offset Calculator
See how width and offset change inner clearance and outer poke.
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Fuel Cost Calculator
Estimate trip fuel, trip cost and annual fuel spending.
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Power-to-Weight
Calculate horsepower per ton and pounds per horsepower.
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RPM & Speed Calculator
Estimate road speed from RPM, tire diameter and gearing.