Enter your new tire size. Get diameter change and gear ratio requirements for your 4WD upgrade.
4WD Tire Size Calculator — Will These Tyres Fit Without Rubbing?
A bigger tyre looks great until it rubs on full lock. Calculate the real-world fit before you buy.
Enter your current tyre size, lift height, and wheel offset. The calculator returns max tyre size, clearance at full lock, and speedometer error.
An oversized tyre that contacts the body or suspension under articulation is a MOT/registration failure. Speedometer error from a size change can also be an MOT issue.
4WD owners, overlanders, and off-road enthusiasts upgrading tyres or fitting a lift kit.
- SAE tyre sizing standards
- FMVSS 139 tyre rating
- State vehicle modification laws
Disclaimer: This tool is provided for educational and informational purposes only and does not constitute legal, safety, or professional advice. Sunferno Automotive Accessories cannot verify how products are installed, used, or attached in your specific vehicle or situation — proper installation, use, and securement are solely the responsibility of the user. Laws and regulations vary by jurisdiction and change over time; always confirm current requirements with your local authorities or a qualified professional. Sunferno products must be used strictly in accordance with manufacturer instructions and applicable regulations.
