Tire & wheel math, done for you

Fast, free calculators for the numbers that decide whether a setup fits: tire dimensions, diameter changes, wheel offset and bolt patterns. No signup, no fluff, just answers.

Tires

Tire Size Calculator

Overall diameter, sidewall height, circumference and revs per mile for any metric tire size.

 Tires

Tire Size Comparison

Compare two tire sizes side by side, with ride height change and a speedometer error table.

 Wheels

Wheel Offset Calculator

See how a new wheel width and offset change poke, inner clearance and backspacing.

 Wheels

Bolt Pattern Calculator

Find your PCD from a simple lug measurement, with a chart of common patterns by vehicle.

 Trips

Fuel Cost Calculator

Trip and road trip gas cost from distance, fuel economy and price, with cost splitting.

 Towing

Towing Capacity

Tow ratings by vehicle and year, plus a real-world calculator from GCWR and curb weight.

 Money

Car Depreciation Calculator

What a car is worth at any age and what ownership really costs per month in lost value.

 Performance

0-60 Times Database

Real-world acceleration times for popular cars, trucks and EVs in one sortable table.

Check fitment before you buy

Most bad wheel and tire purchases come down to three numbers nobody checked: the overall diameter change, the offset change, and the bolt pattern. GarageCalc covers all three in under a minute. Start with the tire comparison to keep your diameter within the safe 3 percent envelope, run the offset calculator to see exactly where the new wheel will sit, and confirm the bolt pattern matches your hub.

Every tool works entirely in your browser, on desktop and mobile, and shows the formulas it uses. Planning a haul instead? Look up towing capacity by vehicle, or price out the drive with the fuel cost calculator, or see what your car is really costing you with the depreciation calculator. Arguing about acceleration? Settle it with the 0-60 times database.