275/40 R20 vs 295/35 R21

295/35 R21 stays within the configured tolerance for 275/40 R20: +1.6% diameter and +1.6% speedometer effect.

Geometric comparison

295/35 R21 stays within the configured tolerance for 275/40 R20: +1.6% diameter and +1.6% speedometer effect.

Geometric comparison
Metric	This size: 275/40 R20	Alternative: 295/35 R21	Difference	Verdict
Overall diameter	28.66 in	29.13 in	+1.6%	Within tolerance
Section width	10.83 in	11.61 in	+0.79 in	Computed difference
Sidewall height	4.33 in	4.06 in	-0.27 in	Computed difference
Circumference	90.04 in	91.51 in	+1.6%	Within tolerance
Speedo	0.0%	+1.6%	+1.6%	Within tolerance

Compare sizes

Current tireLooks valid

New tireLooks valid

Market

Units

Requires verificationWithin tolerance · Diameter +1.6% (+0.47 in) · US (~3%)

Requires verification · This rating covers tire geometry only, not vehicle compatibility.
Diameter +1.6% · Ride-height change +0.23 in.
Speedometer reads low · 60 mph → 61.0 mph.
Sidewall -0.27 in · Width +0.79 in.

Diameter+1.6%+0.47 in

Speedo @ 60+1.6%60 mph → 61.0 mph

Sidewall-0.27 inWidth +0.79 in

Ride-height change+0.23 inDiameter ÷ 2

How this result is calculated

Computed from nominal tire-size geometry: diameter, circumference and speedometer error. It does not check vehicle placard approval, load/speed rating, rim-width range, wheel-arch, suspension or brake clearance.

Methodology

Before fitting

Check the vehicle placard and owner’s manual first.
Match or exceed the required load index and speed rating.
Confirm rim-width range, bolt pattern, hub bore, offset and fasteners.
Inspect wheel-arch, suspension and brake clearance under real vehicle load.
Check TPMS, cold pressure and local roadworthiness rules.

Diameter: 28.66 in 29.13 in+0.47 in
Sidewall: 4.33 in 4.06 in-0.27 in
Width: 10.83 in 11.61 in+0.79 in
Circumference: 90.04 in 91.51 in+1.6%
Revs / mile: 704 692
Speedo @ 60: 60 mph 61.0 mph+1.6%
Ride-height change: 0.00 in +0.23 in
True distance per 100 indicated: 100 mi 101.6 mi+1.6%

Current — 275/40 R20
New — 295/35 R21
Grounded to the road: the axle rises +0.23 in.

Result report

275/40 R20 295/35 R21 · Requires verification · Within tolerance

Plan budget for this size: 295/35 R21

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Plan budget for this size

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Markdown link

[275/40 R20 vs 295/35 R21 Tire size comparison](https://tirefitlab.com/tire-size-calculator/?from=275%2F40+R20&to=295%2F35+R21&market=us)

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Budget$205–$290Per tire Mid-range$270–$380Per tire Premium$385–$540Per tire

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

In-tolerance alternative sizes

In-tolerance alternative sizes
Size	Diameter	Speedo @ 100	Use this
OE `275/40R20`	+0.0%	+0.0%

275/40 R20 · 295/35 R21 · Methodology

Technical check: 2026-06-28

What changed

Checked generated routes, metadata, sitemap inclusion and localized page rendering.

Methodology