Motorcycle Tyre Size Calculator
Look up your bike to auto-fill OEM tyre sizes, or enter any size manually. Compare two sizes and see exactly how a swap affects your speedo reading.
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Current Tyre
Alternative Tyre
How to Read a Motorcycle Tyre Size Code
A tyre code like 160/60/17 breaks down simply. The first number (160) is the tyre width in millimetres. The second (60) is the aspect ratio — the sidewall height as a percentage of the width. The third (17) is the rim diameter in inches.
Does Tyre Size Affect Speedo Reading?
Yes. A larger overall diameter means the wheel covers more ground per revolution, so your speedo reads lower than your actual speed. A smaller diameter makes the speedo over-read. This tool shows the exact percentage difference so you know what to expect after a tyre swap.