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Tyre Size Calculator
Compare two tyre sizes and check fitment safety.
Original tyre size
e.g. 195/65 R15
New tyre size
e.g. 205/55 R16
Overall diameter change
-0.41%
Safe substitution — within ±3% tolerance
Original diameter
635 mm
New diameter
632 mm
Original sidewall
127 mm
New sidewall
113 mm
Speedo error
-0.41%
Revs / km (new)
504
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