205/35R18 tire size
205/35R18 is a metric size: 23.6" tall, 8.1" wide, on a 18" rim — about a 23.5x8.00R18. The sidewall is 2.8" and the tire turns 853 times per mile.
205/35R18 specs
| Overall diameter (height) | 23.65" · 601 mm |
|---|---|
| Section width | 8.07" · 205 mm |
| Sidewall height | 2.82" · 72 mm (35% of width) |
| Rim diameter | 18" |
| Circumference | 74.30" · 1.887 m |
| Revolutions per mile | 853 (530 per km) |
| Inch (flotation) equivalent | 23.5x8.00R18 |
Equivalent sizes on a 18" 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 | |
|---|---|---|---|---|---|
| 245/35R18 common | 24.75" | +4.66% | +40 mm | 62.8 mph | calculate → |
| 215/40R18 | 24.77" | +4.74% | +10 mm | 62.8 mph | calculate → |
| 285/30R18 | 24.73" | +4.58% | +80 mm | 62.7 mph | calculate → |
| 205/40R18 | 24.46" | +3.41% | 0 mm | 62.0 mph | calculate → |
| 215/35R18 | 23.93" | +1.17% | +10 mm | 60.7 mph | calculate → |
| 225/35R18 | 24.20" | +2.33% | +20 mm | 61.4 mph | calculate → |
| 235/35R18 | 24.48" | +3.50% | +30 mm | 62.1 mph | calculate → |
| 235/30R18 | 23.55" | -0.42% | +30 mm | 59.8 mph | calculate → |
Plus / minus sizing: 17" and 19" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 205/40R17 | 23.46" | -0.82% | 0 mm | 59.5 mph | calculate → |
| 215/40R17 | 23.77" | +0.52% | +10 mm | 60.3 mph | calculate → |
| 245/35R17 | 23.75" | +0.43% | +40 mm | 60.3 mph | calculate → |
Try another size against 205/35R18
Questions
What size is 205/35R18 in inches?
205/35R18 is about 23.6" tall and 8.1" wide on a 18-inch rim — roughly a 23.5x8.00R18 in inch sizing.
What does 205/35R18 mean?
205 mm section width, sidewall 35% of the width (2.82"), radial construction, 18-inch rim.
What tire sizes are equivalent to 205/35R18?
On the same 18" rim, within 3% of the diameter: 235/30R18 (-0.42%), 215/35R18 (+1.17%), 225/35R18 (+2.33%), 205/40R18 (+3.41%), 235/35R18 (+3.50%), 285/30R18 (+4.58%).
How many revolutions per mile does a 205/35R18 tire make?
About 853 revolutions per mile (circumference 74.3").
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.