37x13.50 R20

What size is 37x13.50 R20?

37x13.50 R20 has an overall diameter of about 37.00 in, a section width of 13.50 in and a sidewall height of 8.50 in. It turns roughly 545 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

Seasonal check

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

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Specification

Overall diameter37.00 in
Section width13.50 in
Sidewall height8.50 in
Circumference116.24 in
Revolutions 339 /km · 545 /mi

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 +0.00 in · Width +0.00 in.
Diameter+0.0%+0.00 in
Speedo @ 60+0.0%60 mph60.0 mph
Sidewall+0.00 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
37.00 in 37.00 in+0.00 in
Sidewall
8.50 in 8.50 in+0.00 in
Width
13.50 in 13.50 in+0.00 in
Circumference
116.24 in 116.24 in+0.0%
Revs / mile
545 545
Speedo @ 60
60 mph 60.0 mph+0.0%
Δ⌀ +0.0 mm
  • Current37x13.50 R20
  • New37x13.50 R20
  • Grounded to the road: the axle rises +0.00 in.

Result report

37x13.50 R20 37x13.50 R20 · Within tolerance

Use this size when shopping: 37x13.50 R20

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 305/75R19+0.0%+0.0%
OE 335/65R20+0.4%+0.4%
+1″ 255/80R21+0.2%+0.2%
+2″ 255/75R22+0.2%+0.2%

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Last reviewed: 2026-06-28

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