285/40 R22

What size is 285/40 R22?

285/40 R22 has an overall diameter of about 30.98 in, a section width of 11.22 in and a sidewall height of 4.49 in. It turns roughly 651 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

Fitment verdict

31x10.50 R15 stays within the configured tolerance for 285/40 R22: +0.1% diameter and +0.1% speedometer effect.

Metric This size: 285/40 R22 Alternative: 31x10.50 R15 Difference Verdict
Overall diameter 30.98 in 31.00 in +0.1% Within tolerance
Section width 11.22 in 10.50 in -0.72 in Computed difference
Sidewall height 4.49 in 8.00 in +3.51 in Computed difference
Circumference 97.32 in 97.39 in +0.1% Within tolerance
Speedo 0.0% +0.1% +0.1% Within tolerance

Seasonal check

Planning a long summer drive?

Use the budget and running-cost tools before a trip, especially if the current tyres are worn or the replacement size changes diameter.

Estimate tyre budget

Specification

Overall diameter30.98 in
Section width11.22 in
Sidewall height4.49 in
Circumference97.32 in
Revolutions 405 /km · 651 /mi

In-tolerance sizes

Alternative sizes that stay within the safe diameter tolerance:

Size Diameter Speedo Verdict
31x10.50 R15 +0.1% +0.1% ✓ OK
31x10.50 R16 +0.1% +0.1% ✓ OK
275/55 R19 -0.2% -0.2% ✓ OK
275/45 R21 -0.7% -0.7% ✓ OK
285/50 R20 +0.8% +0.8% ✓ OK
265/70 R16 -1.2% -1.2% ✓ OK
265/65 R17 -1.3% -1.3% ✓ OK
245/65 R18 -1.4% -1.4% ✓ OK
265/60 R18 -1.5% -1.5% ✓ OK
245/70 R17 -1.5% -1.5% ✓ OK
285/60 R18 +1.6% +1.6% ✓ OK
265/50 R20 -1.8% -1.8% ✓ OK

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.1% (+0.02 in) · US (~3%)
  • Within tolerance · Diameter +0.1%.
  • Speedo @ 60: 60 mph60.0 mph.
  • Sidewall +3.51 in · Width -0.72 in.
Diameter+0.1%+0.02 in
Speedo @ 60+0.1%60 mph60.0 mph
Sidewall+3.51 inWidth -0.72 in
How this result is calculated

Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check wheel-arch, suspension or brake clearance.

Methodology
Diameter
30.98 in 31.00 in+0.02 in
Sidewall
4.49 in 8.00 in+3.51 in
Width
11.22 in 10.50 in-0.72 in
Circumference
97.32 in 97.39 in+0.1%
Revs / mile
651 651
Speedo @ 60
60 mph 60.0 mph+0.1%
Δ⌀ +0.6 mm
  • Current285/40 R22
  • New31x10.50 R15
  • Grounded to the road: the axle rises +0.01 in.

Result report

285/40 R22 31x10.50 R15 · Within tolerance

Use this size when shopping: 31x10.50 R15

Use this size when shopping

Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 195/65R21+0.0%+0.0%
OE 285/40R22+0.0%+0.0%
+1″ 135/75R23-0.0%-0.0%
+2″ 295/30R24-0.0%-0.0%

More tools

Last reviewed: 2026-06-28

Last reviewed: 2026-06-28
What changed
  • Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.