Tire size reference

245/60R18 tire size: 29.57 in tall

Diameter, sidewall, width and revs per mile for 245/60R18, the common sizes within 3% of its diameter, and what each one does to the speedometer.

In short

245/60R18, in short: 29.57 in (751 mm) tall and 245 mm (9.65 in) wide, with a 5.79 in (147.0 mm) sidewall, for a 18-inch wheel. Circumference is 92.91 in, so it turns about 682 times per mile (calculated from the nominal size).

Overall diameter29.57 in · 751 mm
Section width245 mm · 9.65 in
Sidewall height5.79 in · 147.0 mm
Circumference92.91 in
Revs per mile (calculated)682
In inches29.6x9.6R18

Calculated from the size: sidewall = 245 × 60% = 147.00 mm; diameter = 2 × 5.787 in + 18 in; revs per mile = 63,360 ÷ (π × diameter).

Sizes within 3% of 245/60R18

23 common sizes come within ±3% of 29.57 in: 4 on the same 18-inch wheel, 12 plus-size and 7 minus-size. The last column is what the speedometer shows when the vehicle, set up for 245/60R18, is doing a true 60 mph.

SizeFitDiameterDifferenceWidthSidewallRevs/mile (calc.)Speedometer at a true 60
245/60R18This size29.57 in-245 mm5.79 in68260.0 mph
235/70R16Minus 228.95 in-2.10%235 mm6.48 in69761.3 mph
225/75R16Minus 229.29 in-0.97%225 mm6.64 in68960.6 mph
245/70R16Minus 229.50 in-0.24%245 mm6.75 in68460.1 mph
235/75R16Minus 229.88 in+1.03%235 mm6.94 in67559.4 mph
235/65R17Minus 129.03 in-1.85%235 mm6.01 in69561.1 mph
245/65R17Minus 129.54 in-0.12%245 mm6.27 in68360.1 mph
255/65R17Minus 130.05 in+1.61%255 mm6.53 in67159.0 mph
255/55R18Same wheel29.04 in-1.80%255 mm5.52 in69461.1 mph
235/60R18Same wheel29.10 in-1.60%235 mm5.55 in69361.0 mph
235/65R18Same wheel30.03 in+1.53%235 mm6.01 in67259.1 mph
255/60R18Same wheel30.05 in+1.60%255 mm6.02 in67159.1 mph
225/55R19Plus 128.74 in-2.81%225 mm4.87 in70261.7 mph
255/50R19Plus 129.04 in-1.81%255 mm5.02 in69561.1 mph
235/55R19Plus 129.18 in-1.34%235 mm5.09 in69160.8 mph
265/50R19Plus 129.43 in-0.48%265 mm5.22 in68560.3 mph
245/55R19Plus 129.61 in+0.12%245 mm5.31 in68159.9 mph
255/55R19Plus 130.04 in+1.58%255 mm5.52 in67159.1 mph
255/45R20Plus 229.04 in-1.82%255 mm4.52 in69561.1 mph
245/50R20Plus 229.65 in+0.24%245 mm4.82 in68059.9 mph
275/45R20Plus 229.74 in+0.57%275 mm4.87 in67859.7 mph
255/50R20Plus 230.04 in+1.57%255 mm5.02 in67159.1 mph
235/55R20Plus 230.18 in+2.04%235 mm5.09 in66858.8 mph
265/50R20Plus 230.43 in+2.90%265 mm5.22 in66358.3 mph

A taller tire makes the speedometer read low, a shorter one high. Plus-sizing keeps the diameter close by trading sidewall for wheel. Any replacement needs a load index at least as high as the vehicle's tire placard calls for, and a wheel width the tire is approved for.

245/60R18 compared

245/60R18 side by side with 255/60R18 and 235/60R18: dimension by dimension, and what the swap does to the speedometer.

245/60R18 vs 255/60R18

+1.60% diameter
245/60R18255/60R18Difference
Overall diameter29.57 in30.05 in+0.47 in (+1.6%)
Section width245 mm255 mm+10 mm
Sidewall height5.79 in6.02 in+0.24 in
Wheel diameter18 in18 in+0 in
Circumference92.9 in94.4 in+1.5 in
Revs per mile (calc.)682671-11

255/60R18 is 1.6% taller than 245/60R18. At a true 60 mph the speedometer shows 59.1 mph (it reads low), and when it shows 60 you're doing 61.0 mph.

Compare in the calculator

245/60R18 vs 235/60R18

-1.60% diameter
245/60R18235/60R18Difference
Overall diameter29.57 in29.10 in-0.47 in (-1.6%)
Section width245 mm235 mm-10 mm
Sidewall height5.79 in5.55 in-0.24 in
Wheel diameter18 in18 in+0 in
Circumference92.9 in91.4 in-1.5 in
Revs per mile (calc.)682693+11

235/60R18 is 1.6% shorter than 245/60R18. At a true 60 mph the speedometer shows 61.0 mph (it reads high), and when it shows 60 you're doing 59.0 mph.

Compare in the calculator

Which vehicles come with 245/60R18

Vehicles sold in the US that have 245/60R18 as the standard size on these trims, with the page that lists it. The tire placard on the driver's door edge or post has the size, and the load and inflation, for the exact vehicle.

Vehicles mostly picked from Carscoops: 2025 U.S. car sales, full-year top 25 (Car and Driver data, January 2026).

FAQ

Questions about 245/60R18 tires

How tall is a 245/60R18 tire?
29.57 inches (751 mm) overall. The sidewall is 245 × 60% = 147.00 mm (5.79 in); twice that plus the 18-inch wheel gives 29.57 in. That's the nominal size: the maker's spec sheet lists the measured diameter for each tire.
What is 245/60R18 in inches?
About 29.6x9.6R18: 29.57 in tall, 9.65 in wide, for a 18-inch wheel, with a 5.79 in sidewall.
How many revolutions per mile does a 245/60R18 tire make?
About 682, calculated as 63,360 in ÷ (92.91 in circumference). Makers measure revs per mile under load, where the tire squats a little, so their published figure for a given tire is usually somewhat higher.
What size can replace 245/60R18?
The usual guideline is to stay within 3% of the original 29.57 in diameter, which keeps the speedometer, gearing and stability systems close. The closest common ones are 245/55R19 (+0.1%, 19-inch wheel); 245/65R17 (-0.1%, 17-inch wheel); 245/70R16 (-0.2%, 16-inch wheel). A replacement also needs a load index at least as high as the vehicle's placard calls for and a wheel of the right width.
245/60R18 vs 255/60R18: what's the difference?
255/60R18 is 1.6% taller than 245/60R18. At a true 60 mph the speedometer shows 59.1 mph (it reads low), and when it shows 60 you're doing 61.0 mph.
Which vehicles come with 245/60R18 tires?
It's the standard size on the 2025 Kia Telluride LX, EX X-Pro, SX Prestige X-Pro; 2025 Hyundai Palisade SE, SEL; 2025 Subaru Ascent Premium. Always go by the size on the vehicle's tire placard (driver's door edge or post) or in the owner's manual.
Sources

How these numbers are worked out

Checked October 2026. Dimensions are nominal, calculated from the size designation. A real tire's diameter, width and revs per mile vary by brand, tread depth, rim width and load, so check the maker's spec sheet.

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