315/30R23 tire size
315/30R23 is a metric size: 30.4" tall, 12.4" wide, on a 23" rim — about a 30.5x12.50R23. The sidewall is 3.7" and the tire turns 663 times per mile.
315/30R23 specs
| Overall diameter (height) | 30.44" · 773 mm |
|---|---|
| Section width | 12.40" · 315 mm |
| Sidewall height | 3.72" · 95 mm (30% of width) |
| Rim diameter | 23" |
| Circumference | 95.63" · 2.429 m |
| Revolutions per mile | 663 (412 per km) |
| Inch (flotation) equivalent | 30.5x12.50R23 |
Equivalent sizes on a 23" rim
Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 285/35R23 | 30.85" | +1.36% | -30 mm | 60.8 mph | calculate → |
| 295/35R23 | 31.13" | +2.26% | -20 mm | 61.4 mph | calculate → |
| 325/30R23 | 30.68" | +0.78% | +10 mm | 60.5 mph | calculate → |
| 335/30R23 | 30.91" | +1.55% | +20 mm | 60.9 mph | calculate → |
| 255/40R23 | 31.03" | +1.94% | -60 mm | 61.2 mph | calculate → |
| 275/35R23 | 30.58" | +0.45% | -40 mm | 60.3 mph | calculate → |
| 295/30R23 | 29.97" | -1.55% | -20 mm | 59.1 mph | calculate → |
Try another size against 315/30R23
Questions
What size is 315/30R23 in inches?
315/30R23 is about 30.4" tall and 12.4" wide on a 23-inch rim — roughly a 30.5x12.50R23 in inch sizing.
What does 315/30R23 mean?
315 mm section width, sidewall 30% of the width (3.72"), radial construction, 23-inch rim.
What tire sizes are equivalent to 315/30R23?
On the same 23" rim, within 3% of the diameter: 275/35R23 (+0.45%), 325/30R23 (+0.78%), 285/35R23 (+1.36%), 295/30R23 (-1.55%), 335/30R23 (+1.55%), 255/40R23 (+1.94%).
How many revolutions per mile does a 315/30R23 tire make?
About 663 revolutions per mile (circumference 95.6").
How these numbers are computed
Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.