265/45R20 vs 245/45R20 tire size comparison

Change either size and everything below updates.

Start from your car make, model, year

Make Model Year

Width/AspectRRim

DiameterxWidthRRim

Width/AspectRRim

DiameterxWidthRRim

Width in mm · aspect = sidewall height as a % of width · rim in inches

Flotation (LT) sizes, all in inches: overall diameter × section width, then rim

Within the usual 3% rule

−2.41% diameter

Most fitment guides accept up to 3%. Check clearance at full lock and full suspension compression before committing.

20 mm narrower: check the tire is approved for your rim width.

Tires in 245/45R20

Check price on Amazon · 245/45R20 Best-rated 245/45R20 tires

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Measurement	265/45R20	245/45R20	Diff	%
Overall diameter	29.39″747 mm	28.68″729 mm	−0.71″	−2.4%
Section width	265.0 mm	245.0 mm	−20.0 mm	−7.5%
Sidewall height	119.3 mm	110.3 mm	−9.0 mm	−7.5%
Rim diameter	20″	20″	0″	0.0%
Circumference	92.33″2345 mm	90.10″2289 mm	−2.23″	−2.4%
Revolutions per mileturns per distance; drives the odometer	686426 /km	703437 /km	+17	+2.5%
Ride height change	—	—	−0.35″ −9.0 mm

Speedometer reading

Speedo shows

60mph

97 km/h

Actual speed

58.6mph

94 km/h

Overlay

265/45R20245/45R20

How to use the tire size calculator

Put your current tire size — width, aspect ratio and rim diameter — into the first form, then your desired size into the second. You’ll get the difference between the new and the old size, plus the speedometer reading difference and your actual speed on the new set. Both metric and flotation (LT inch) sizes are supported.

The calculator helps you decide whether a set of tires and wheels will fit your car. To compare tires by brand and model instead, use our tire comparison tool; to look up factory sizes, browse by car make.