245/35 R20

What size is 245/35 R20?

245/35 R20 has an overall diameter of about 26.75 in, a section width of 9.65 in and a sidewall height of 3.38 in. It turns roughly 754 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

Fitment verdict

225/55 R17 stays within the configured tolerance for 245/35 R20: 0.0% diameter and 0.0% speedometer effect.

Metric This size: 245/35 R20 Alternative: 225/55 R17 Difference Verdict
Overall diameter 26.75 in 26.74 in 0.0% Within tolerance
Section width 9.65 in 8.86 in -0.79 in Computed difference
Sidewall height 3.38 in 4.87 in +1.50 in Computed difference
Circumference 84.04 in 84.02 in 0.0% Within tolerance
Speedo 0.0% 0.0% 0.0% Within tolerance

Seasonal check

Planning a long summer drive?

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

Estimate tyre budget

Specification

Overall diameter26.75 in
Section width9.65 in
Sidewall height3.38 in
Circumference84.04 in
Revolutions 468 /km · 754 /mi

In-tolerance sizes

Alternative sizes that stay within the safe diameter tolerance:

Size Diameter Speedo Verdict
225/55 R17 -0.0% -0.0% ✓ OK
245/40 R19 -0.1% -0.1% ✓ OK
245/45 R18 -0.3% -0.3% ✓ OK
215/70 R15 +0.4% +0.4% ✓ OK
225/60 R16 -0.5% -0.5% ✓ OK
215/65 R16 +0.9% +0.9% ✓ OK
255/35 R20 +1.0% +1.0% ✓ OK
255/40 R19 +1.0% +1.0% ✓ OK
255/45 R18 +1.1% +1.1% ✓ OK
235/60 R16 +1.3% +1.3% ✓ OK
215/60 R17 +1.5% +1.5% ✓ OK
235/55 R17 +1.6% +1.6% ✓ OK

Compare sizes

Looks valid
Looks valid
Units
✓ Within toleranceDiameter -0.0% (-0.01 in) · US (~3%)
  • Within tolerance · Diameter -0.0%.
  • Speedo @ 60: 60 mph60.0 mph.
  • Sidewall +1.50 in · Width -0.79 in.
Diameter-0.0%-0.01 in
Speedo @ 60-0.0%60 mph60.0 mph
Sidewall+1.50 inWidth -0.79 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
26.75 in 26.74 in-0.01 in
Sidewall
3.38 in 4.87 in+1.50 in
Width
9.65 in 8.86 in-0.79 in
Circumference
84.04 in 84.02 in-0.0%
Revs / mile
754 754
Speedo @ 60
60 mph 60.0 mph-0.0%
Δ⌀ −0.2 mm
  • Current245/35 R20
  • New225/55 R17
  • Grounded to the road: the axle rises -0.00 in.

Result report

245/35 R20 225/55 R17 · Within tolerance

Use this size when shopping: 225/55 R17

Use this size when shopping

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

Safe alternative sizes

SizeDiameterSpeedo @ 100Use this
−1″ 245/40R19-0.1%-0.1%
OE 245/35R20+0.0%+0.0%
+1″ 245/30R21+0.1%+0.1%
+2″ 135/45R22+0.1%+0.1%

More tools

Last reviewed: 2026-06-28

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