275/45 R21 vs 31x10.50 R15
275/45 R21 vs 31x10.50 R15
31x10.50 R15 stays within the configured tolerance for 275/45 R21: +0.8% diameter and +0.8% speedometer effect.
Fitment verdict
31x10.50 R15 stays within the configured tolerance for 275/45 R21: +0.8% diameter and +0.8% speedometer effect.
| Metric | This size: 275/45 R21 | Alternative: 31x10.50 R15 | Difference | Verdict |
|---|---|---|---|---|
| Overall diameter | 30.74 in | 31.00 in | +0.8% | Within tolerance |
| Section width | 10.83 in | 10.50 in | -0.33 in | Computed difference |
| Sidewall height | 4.87 in | 8.00 in | +3.13 in | Computed difference |
| Circumference | 96.59 in | 97.39 in | +0.8% | Within tolerance |
| Speedo | 0.0% | +0.8% | +0.8% | Within tolerance |
Compare sizes
Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.8% (+0.26 in) · US (~3%)
- Within tolerance · Diameter +0.8%.
- Speedo @ 60: 60 mph → 60.5 mph.
- Sidewall +3.13 in · Width -0.33 in.
Diameter+0.8%+0.26 in
Speedo @ 60+0.8%60 mph → 60.5 mph
Sidewall+3.13 inWidth -0.33 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
- 30.74 in 31.00 in+0.26 in
- Sidewall
- 4.87 in 8.00 in+3.13 in
- Width
- 10.83 in 10.50 in-0.33 in
- Circumference
- 96.59 in 97.39 in+0.8%
- Revs / mile
- 656 651
- Speedo @ 60
- 60 mph 60.5 mph+0.8%
- Current —
275/45 R21 - New —
31x10.50 R15 - Grounded to the road: the axle rises +0.13 in.
Result report
275/45 R21 31x10.50 R15 · Within tolerance
Use this size when shopping: 31x10.50 R15
Geometric estimate. Always verify physical clearance (arches, suspension, brakes) before fitting.
Safe alternative sizes
| Size | Diameter | Speedo @ 100 | Use this |
|---|---|---|---|
−1″ 195/70R20 | +0.0% | +0.0% | |
OE 275/45R21 | +0.0% | +0.0% | |
+1″ 185/60R22 | -0.0% | -0.0% | |
+2″ 245/40R23 | -0.1% | -0.1% |
275/45 R21 · 31x10.50 R15 · Methodology
What changed
- Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.