125/80R13 Tire Size
125/80R13 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 125/80R13 tire size breaks down as: 125 mm section width, 80% aspect ratio, and a 13-inch rim. Below are its real, calculated dimensions.
125/80R13 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 20.9 in (530 mm) |
| Sidewall height | 3.9 in (100 mm) |
| Circumference | 65.6 in (1666 mm) |
| Revolutions per mile | 966 |
Typical Fitment
125/80R13 is most often found on compact cars and space-saver spares. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 125/80R13, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 135/75R13 | 20.97 in | +0.5% |
| 135/65R14 | 20.91 in | +0.2% |
| 145/50R15 | 20.71 in | -0.8% |
Speedometer Note
If you fit a 135/75R13 instead of 125/80R13, the diameter changes by +0.5%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 60 mph. A shorter tire has the opposite effect, so the gauge reads high.
Use the tire calculator to compare 125/80R13 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 125/80R13 mean?
125/80R13 means a 125 mm wide tire with a 80% sidewall aspect ratio mounted on a 13-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 125/80R13?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 125/80R13 are 135/75R13, 135/65R14, 145/50R15.
Will 125/80R13 affect my speedometer?
Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.