TireFitLab

245/70 R16 vs 35x12.50 R20

245/70 R16 vs 35x12.50 R20

35x12.50 R20 is outside the configured tolerance for 245/70 R16: +18.6% diameter and +18.6% speedometer effect.

Fitment verdict

35x12.50 R20 is outside the configured tolerance for 245/70 R16: +18.6% diameter and +18.6% speedometer effect.

Metric This size: 245/70 R16 Alternative: 35x12.50 R20 Difference Verdict
Overall diameter 29.50 in 35.00 in +18.6% Too tall
Section width 9.65 in 12.50 in +2.85 in Computed difference
Sidewall height 6.75 in 7.50 in +0.75 in Computed difference
Circumference 92.69 in 109.96 in +18.6% Too tall
Speedo 0.0% +18.6% +18.6% Outside tolerance

Compare sizes

Looks valid
Looks valid
Units
✕ Out of toleranceDiameter +18.6% (+5.50 in) · US (~3%)
  • Out of tolerance · Diameter +18.6%.
  • Speedo @ 60: 60 mph → 71.2 mph.
  • Sidewall +0.75 in · Width +2.85 in.
Diameter+18.6%+5.50 in
Speedo @ 60+18.6%60 mph → 71.2 mph
Sidewall+0.75 inWidth +2.85 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
29.50 in 35.00 in+5.50 in
Sidewall
6.75 in 7.50 in+0.75 in
Width
9.65 in 12.50 in+2.85 in
Circumference
92.69 in 109.96 in+18.6%
Revs / mile
684 576
Speedo @ 60
60 mph 71.2 mph+18.6%
Δ⌀ +139.6 mm
  • Current — 245/70 R16
  • New — 35x12.50 R20
  • Grounded to the road: the axle rises +2.75 in.

Result report

245/70 R16 35x12.50 R20 · Out of tolerance

Use this size when shopping: 35x12.50 R20

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 335/55R15+0.0%+0.0%
OE 245/70R16+0.0%+0.0%
+1″ 265/60R17+0.1%+0.1%
+2″ 195/75R18+0.0%+0.0%

245/70 R16 · 35x12.50 R20 · Methodology

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