Garage calculators

Work through tire labels, drivetrain ratios and fuel-mix arithmetic without turning a geometric result into a compatibility or safety claim.

Calculators in this section

Calculate theoretical diameter and circumference.

Compare the geometry of two metric tire labels.

Estimate geometric speed change from tire diameter.

Relate speed and RPM through tire and gear ratios.

Calculate oil from a manufacturer-specified ratio.

Compare inner clearance and outer wheel position.

Calculate static ratio from cylinder and clearance geometry.

Calculate total displacement from bore, stroke and cylinders.

Compare horsepower and vehicle weight in common units.

Find chain-drive ratio and driven sprocket RPM.

Estimate per-cylinder fuel flow from explicit assumptions.

Tire dimensions come from the size label and drivetrain results assume no slip. Real measurements and manufacturer tolerances can differ.

These tools do not approve a wheel, tire, speed, RPM or mixture. Vehicle, tire and equipment manufacturers remain the authoritative sources.

Does a small tire-size difference mean the tire fits?

No. Fitment also depends on wheel width and offset, clearance, load and speed ratings, and vehicle systems.

Does the mix calculator choose the correct ratio?

No. Enter only the ratio specified by the equipment manufacturer.