Tire size reference

245/70R17 tire size: 30.50 in tall

Diameter, sidewall, width and revs per mile for 245/70R17, the common sizes within 3% of its diameter, and what each one does to the speedometer.

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In short

245/70R17, in short: 30.50 in (775 mm) tall and 245 mm (9.65 in) wide, with a 6.75 in (171.5 mm) sidewall, for a 17-inch wheel. Circumference is 95.83 in, so it turns about 661 times per mile (calculated from the nominal size).

Overall diameter30.50 in · 775 mm
Section width245 mm · 9.65 in
Sidewall height6.75 in · 171.5 mm
Circumference95.83 in
Revs per mile (calculated)661
In inches30.5x9.6R17

Calculated from the size: sidewall = 245 × 70% = 171.50 mm; diameter = 2 × 6.752 in + 17 in; revs per mile = 63,360 ÷ (π × diameter).

Sizes within 3% of 245/70R17

12 common sizes come within ±3% of 30.50 in: 3 on the same 17-inch wheel, 6 plus-size and 3 minus-size. The last column is what the speedometer shows when the vehicle, set up for 245/70R17, is doing a true 60 mph.

SizeFitDiameterDifferenceWidthSidewallRevs/mile (calc.)Speedometer at a true 60
245/70R17This size30.50 in-245 mm6.75 in66160.0 mph
235/75R16Minus 129.88 in-2.05%235 mm6.94 in67561.3 mph
245/75R16Minus 130.47 in-0.12%245 mm7.23 in66260.1 mph
265/70R16Minus 130.61 in+0.34%265 mm7.30 in65959.8 mph
255/65R17Same wheel30.05 in-1.48%255 mm6.53 in67160.9 mph
265/65R17Same wheel30.56 in+0.19%265 mm6.78 in66059.9 mph
255/70R17Same wheel31.06 in+1.81%255 mm7.03 in64958.9 mph
235/65R18Plus 130.03 in-1.56%235 mm6.01 in67261.0 mph
255/60R18Plus 130.05 in-1.50%255 mm6.02 in67160.9 mph
265/60R18Plus 130.52 in+0.05%265 mm6.26 in66160.0 mph
255/65R18Plus 131.05 in+1.79%255 mm6.53 in65058.9 mph
245/55R19Plus 229.61 in-2.93%245 mm5.31 in68161.8 mph
255/55R19Plus 230.04 in-1.51%255 mm5.52 in67160.9 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.

245/70R17 compared

245/70R17 side by side with 265/70R17 and 255/70R17: dimension by dimension, and what the swap does to the speedometer.

245/70R17 vs 265/70R17

+3.61% diameter
245/70R17265/70R17Difference
Overall diameter30.50 in31.61 in+1.10 in (+3.6%)
Section width245 mm265 mm+20 mm
Sidewall height6.75 in7.30 in+0.55 in
Wheel diameter17 in17 in+0 in
Circumference95.8 in99.3 in+3.5 in
Revs per mile (calc.)661638-23

265/70R17 is 3.6% taller than 245/70R17. At a true 60 mph the speedometer shows 57.9 mph (it reads low), and when it shows 60 you're doing 62.2 mph.

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245/70R17 vs 255/70R17

+1.81% diameter
245/70R17255/70R17Difference
Overall diameter30.50 in31.06 in+0.55 in (+1.8%)
Section width245 mm255 mm+10 mm
Sidewall height6.75 in7.03 in+0.28 in
Wheel diameter17 in17 in+0 in
Circumference95.8 in97.6 in+1.7 in
Revs per mile (calc.)661649-12

255/70R17 is 1.8% taller than 245/70R17. At a true 60 mph the speedometer shows 58.9 mph (it reads low), and when it shows 60 you're doing 61.1 mph.

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Which vehicles come with 245/70R17

Vehicles sold in the US that have 245/70R17 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 245/70R17 tires

How tall is a 245/70R17 tire?
30.50 inches (775 mm) overall. The sidewall is 245 × 70% = 171.50 mm (6.75 in); twice that plus the 17-inch wheel gives 30.50 in. That's the nominal size: the maker's spec sheet lists the measured diameter for each tire.
What is 245/70R17 in inches?
About 30.5x9.6R17: 30.50 in tall, 9.65 in wide, for a 17-inch wheel, with a 6.75 in sidewall.
How many revolutions per mile does a 245/70R17 tire make?
About 661, calculated as 63,360 in ÷ (95.83 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 245/70R17?
The usual guideline is to stay within 3% of the original 30.50 in diameter, which keeps the speedometer, gearing and stability systems close. The closest common ones are 265/60R18 (+0.1%, 18-inch wheel); 245/75R16 (-0.1%, 16-inch wheel); 265/65R17 (+0.2%, same 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.
245/70R17 vs 265/70R17: what's the difference?
265/70R17 is 3.6% taller than 245/70R17. At a true 60 mph the speedometer shows 57.9 mph (it reads low), and when it shows 60 you're doing 62.2 mph. That's outside the usual 3% guideline, so check clearance and the speedometer before you fit it.
Which vehicles come with 245/70R17 tires?
It's the standard size on the 2025 Ford F-150 XL 4x2; 2026 Toyota Tacoma SR, SR5; 2026 Toyota 4Runner SR5; 2025 Jeep Grand Cherokee Laredo, Laredo A. 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.

More tire sizes

All tire sizes
265/70R1630.6 in265/65R1730.6 in255/70R1731.1 in265/70R1731.6 in285/70R1732.7 in245/75R1731.5 in265/65R1831.6 in275/65R1832.1 in265/70R1832.6 in275/55R2031.9 in275/60R2033.0 in

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