305/40R22 tire size
305/40R22 is a metric size: 31.6" tall, 12.0" wide, on a 22" rim — about a 31.5x12.00R22. The sidewall is 4.8" and the tire turns 638 times per mile.
305/40R22 specs
| Overall diameter (height) | 31.61" · 803 mm |
|---|---|
| Section width | 12.01" · 305 mm |
| Sidewall height | 4.80" · 122 mm (40% of width) |
| Rim diameter | 22" |
| Circumference | 99.29" · 2.522 m |
| Revolutions per mile | 638 (396 per km) |
| Inch (flotation) equivalent | 31.5x12.00R22 |
Equivalent sizes on a 22" 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 | |
|---|---|---|---|---|---|
| 285/45R22 common | 32.10" | +1.56% | -20 mm | 60.9 mph | compare → |
| 275/50R22 common | 32.83" | +3.86% | -30 mm | 62.3 mph | compare → |
| 275/40R22 | 30.66" | -2.99% | -30 mm | 58.2 mph | compare → |
| 265/40R22 | 30.35" | -3.99% | -40 mm | 57.6 mph | compare → |
| 285/40R22 | 30.98" | -1.99% | -20 mm | 58.8 mph | compare → |
| 305/45R22 | 32.81" | +3.80% | 0 mm | 62.3 mph | compare → |
| 33x12.50R22 | 33.00" | +4.41% | +13 mm | 62.6 mph | compare → |
| 275/45R22 | 31.74" | +0.44% | -30 mm | 60.3 mph | compare → |
| 325/35R22 | 30.96" | -2.06% | +20 mm | 58.8 mph | compare → |
| 315/35R22 | 30.68" | -2.93% | +10 mm | 58.2 mph | compare → |
| 295/35R22 | 30.13" | -4.67% | -10 mm | 57.2 mph | compare → |
| 295/40R22 | 31.29" | -1.00% | -10 mm | 59.4 mph | compare → |
| 255/40R22 | 30.03" | -4.98% | -50 mm | 57.0 mph | compare → |
| 255/45R22 | 31.04" | -1.81% | -50 mm | 58.9 mph | calculate → |
| 325/40R22 | 32.24" | +1.99% | +20 mm | 61.2 mph | calculate → |
| 265/50R22 | 32.43" | +2.62% | -40 mm | 61.6 mph | calculate → |
| 305/35R22 | 30.41" | -3.80% | 0 mm | 57.7 mph | calculate → |
| 315/45R22 | 33.16" | +4.92% | +10 mm | 63.0 mph | calculate → |
| 355/40R22 | 33.18" | +4.98% | +50 mm | 63.0 mph | calculate → |
| 33x13.50R22 | 33.00" | +4.41% | +38 mm | 62.6 mph | calculate → |
| 33x14.50R22 | 33.00" | +4.41% | +63 mm | 62.6 mph | calculate → |
| 265/45R22 | 31.39" | -0.69% | -40 mm | 59.6 mph | calculate → |
Plus / minus sizing: 21" and 23" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 275/50R21 | 31.83" | +0.70% | -30 mm | 60.4 mph | compare → |
| 275/40R23 | 31.66" | +0.17% | -30 mm | 60.1 mph | calculate → |
| 305/35R23 | 31.41" | -0.64% | 0 mm | 59.6 mph | calculate → |
Try another size against 305/40R22
Questions
What size is 305/40R22 in inches?
305/40R22 is about 31.6" tall and 12.0" wide on a 22-inch rim — roughly a 31.5x12.00R22 in inch sizing.
What does 305/40R22 mean?
305 mm section width, sidewall 40% of the width (4.80"), radial construction, 22-inch rim.
What tire sizes are equivalent to 305/40R22?
On the same 22" rim, within 3% of the diameter: 275/45R22 (+0.44%), 265/45R22 (-0.69%), 295/40R22 (-1.00%), 285/45R22 (+1.56%), 255/45R22 (-1.81%), 285/40R22 (-1.99%).
How many revolutions per mile does a 305/40R22 tire make?
About 638 revolutions per mile (circumference 99.3").
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.