Automotive Tools & Calculators
Free tools to help you find the perfect tires and wheels for your vehicle
Tire Size Calculator
Compare tire sizes side-by-side. Calculate diameter difference, speedometer error, and find matching tires.
- Compare two tire sizes
- Speedometer error calculation
- Visual tire overlay
- Plus/minus sizing
Wheel Offset Calculator
Compare wheel fitment. Calculate poke, tuck, backspacing, and verify fender clearance.
- Offset and backspacing
- Poke/tuck calculation
- Fender clearance
- Tire stretch indicator
Frequently Asked Questions
Are these calculators free to use?
Yes! All our automotive calculators are completely free to use. No registration required.
How accurate are the calculations?
Our calculators use industry-standard formulas for tire and wheel measurements. The results are accurate for the measurements you provide. For specific vehicle fitment, always verify with a professional.
Can I save or share my calculations?
Yes! Each calculator generates a shareable URL with your inputs. You can bookmark the page or share the link with others to show your exact calculation.