TireFitLab

235/70 R17 vs 35x12.50 R18

235/70 R17 vs 35x12.50 R18

35x12.50 R18 is outside the configured tolerance for 235/70 R17: +16.9% diameter and +16.9% speedometer effect.

Fitment verdict

35x12.50 R18 is outside the configured tolerance for 235/70 R17: +16.9% diameter and +16.9% speedometer effect.

Metric This size: 235/70 R17 Alternative: 35x12.50 R18 Difference Verdict
Overall diameter 29.95 in 35.00 in +16.9% Too tall
Section width 9.25 in 12.50 in +3.25 in Computed difference
Sidewall height 6.48 in 8.50 in +2.02 in Computed difference
Circumference 94.10 in 109.96 in +16.9% Too tall
Speedo 0.0% +16.9% +16.9% Outside tolerance

Compare sizes

Looks valid
Looks valid
Units
✕ Out of toleranceDiameter +16.9% (+5.05 in) · US (~3%)
  • Out of tolerance · Diameter +16.9%.
  • Speedo @ 60: 60 mph → 70.1 mph.
  • Sidewall +2.02 in · Width +3.25 in.
Diameter+16.9%+5.05 in
Speedo @ 60+16.9%60 mph → 70.1 mph
Sidewall+2.02 inWidth +3.25 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
29.95 in 35.00 in+5.05 in
Sidewall
6.48 in 8.50 in+2.02 in
Width
9.25 in 12.50 in+3.25 in
Circumference
94.10 in 109.96 in+16.9%
Revs / mile
673 576
Speedo @ 60
60 mph 70.1 mph+16.9%
Δ⌀ +128.2 mm
  • Current — 235/70 R17
  • New — 35x12.50 R18
  • Grounded to the road: the axle rises +2.52 in.

Result report

235/70 R17 35x12.50 R18 · Out of tolerance

Use this size when shopping: 35x12.50 R18

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 295/60R16-0.1%-0.1%
OE 235/70R17+0.0%+0.0%
+1″ 275/55R18-0.1%-0.1%
+2″ 185/75R19-0.1%-0.1%

235/70 R17 · 35x12.50 R18 · Methodology

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