Using our tyre size calculator makes choosing the right tyres simple, fast, and completely accurate. Whether you’re checking for a replacement tyre, comparing sizes, or confirming compatibility before a mobile tyre fitting, this tool gives you instant results based on your current tyre dimensions. Enter your tyre width, aspect ratio, and rim size to see matching tyre sizes and alternatives that fit safely.
Tyre Size Calculator
Tire Size Calculator
Our tyre size calculator is designed to help you avoid mistakes, save time, and understand the correct tyre specifications for your vehicle. Every calculation shows your tyre diameter, sidewall height, wheel size, rolling circumference and the effect of any size changes. This helps you choose tyres that work correctly with your suspension, speedometer, handling, braking and safety systems.
When you know your correct tyre size, 24/7 Tyre Assist can supply and fit the replacement tyre quickly. If you’re dealing with a flat tyre, puncture, blowout or slow puncture, our mobile tyre fitters bring the correct tyre directly to your location — often within 30 minutes — and complete the fitting roadside, at home, or at your workplace.
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