33x12.50 R15 vs 33x12.50 R18

33x12.50 R15 vs 33x12.50 R18

33x12.50 R18 stays within the configured tolerance for 33x12.50 R15: 0.0% diameter and 0.0% speedometer effect.

Fitment verdict

33x12.50 R18 stays within the configured tolerance for 33x12.50 R15: 0.0% diameter and 0.0% speedometer effect.

Metric This size: 33x12.50 R15 Alternative: 33x12.50 R18 Difference Verdict
Overall diameter 33.00 in 33.00 in 0.0% Within tolerance
Section width 12.50 in 12.50 in 0.00 in Computed difference
Sidewall height 9.00 in 7.50 in -1.50 in Computed difference
Circumference 103.67 in 103.67 in 0.0% Within tolerance
Speedo 0.0% 0.0% 0.0% Within tolerance

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter +0.0% (+0.00 in) · US (~3%)
  • Within tolerance · Diameter +0.0%.
  • Speedo @ 60: 60 mph60.0 mph.
  • Sidewall -1.50 in · Width +0.00 in.
Diameter+0.0%+0.00 in
Speedo @ 60+0.0%60 mph60.0 mph
Sidewall-1.50 inWidth +0.00 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
33.00 in 33.00 in+0.00 in
Sidewall
9.00 in 7.50 in-1.50 in
Width
12.50 in 12.50 in+0.00 in
Circumference
103.67 in 103.67 in+0.0%
Revs / mile
611 611
Speedo @ 60
60 mph 60.0 mph+0.0%
Δ⌀ +0.0 mm
  • Current33x12.50 R15
  • New33x12.50 R18
  • Grounded to the road: the axle rises +0.00 in.

Result report

33x12.50 R15 33x12.50 R18 · Within tolerance

Use this size when shopping: 33x12.50 R18

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 345/70R14+0.0%+0.0%
OE 305/75R15+0.0%+0.0%
+1″ 335/65R16+0.4%+0.4%
+2″ 255/80R17+0.2%+0.2%

33x12.50 R15 · 33x12.50 R18 · Methodology

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