275/45 R21 vs 31x10.50 R16

31x10.50 R16 stays within the configured tolerance for 275/45 R21: +0.8% diameter and +0.8% speedometer effect.

Geometric comparison

31x10.50 R16 stays within the configured tolerance for 275/45 R21: +0.8% diameter and +0.8% speedometer effect.

Geometric comparison
Metric	This size: 275/45 R21	Alternative: 31x10.50 R16	Difference	Verdict
Overall diameter	30.74 in	31.00 in	+0.8%	Within tolerance
Section width	10.83 in	10.50 in	-0.33 in	Computed difference
Sidewall height	4.87 in	7.50 in	+2.63 in	Computed difference
Circumference	96.59 in	97.39 in	+0.8%	Within tolerance
Speedo	0.0%	+0.8%	+0.8%	Within tolerance

Compare sizes

Current tireLooks valid

New tireLooks valid

Market

Units

Not recommendedWithin tolerance · Diameter +0.8% (+0.26 in) · US (~3%)

Not recommended · This rating covers tire geometry only, not vehicle compatibility.
Diameter +0.8% · Ride-height change +0.13 in.
Speedometer reads low · 60 mph → 60.5 mph.
Sidewall +2.63 in · Width -0.33 in.

Diameter+0.8%+0.26 in

Speedo @ 60+0.8%60 mph → 60.5 mph

Sidewall+2.63 inWidth -0.33 in

Ride-height change+0.13 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: 30.74 in 31.00 in+0.26 in
Sidewall: 4.87 in 7.50 in+2.63 in
Width: 10.83 in 10.50 in-0.33 in
Circumference: 96.59 in 97.39 in+0.8%
Revs / mile: 656 651
Speedo @ 60: 60 mph 60.5 mph+0.8%
Ride-height change: 0.00 in +0.13 in
True distance per 100 indicated: 100 mi 100.8 mi+0.8%

Current — 275/45 R21
New — 31x10.50 R16
Grounded to the road: the axle rises +0.13 in.

Result report

275/45 R21 31x10.50 R16 · Not recommended · Within tolerance

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Markdown link

[275/45 R21 vs 31x10.50 R16 Tire size comparison](https://tirefitlab.com/tire-size-calculator/?from=275%2F45+R21&to=31x10.50+R16&market=us)

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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 `275/45R21`	+0.0%	+0.0%

275/45 R21 · 31x10.50 R16 · Methodology

Technical check: 2026-06-28

What changed

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

Methodology