Tire Size Box

245/70R13 vs 245/80R13

245/80R13 compared with 245/70R13

+7.3% diameter, 0.0" width

245/80R13 is 28.43" tall vs 26.50". More than the 3% rule of thumb, so check carefully before switching.

26.5"13" rim6.8"9.6" wide
245/70R13 (solid) compared with 245/80R13 (dashed outline), drawn to scale

With 245/80R13 tires, when your speedometer says 60 mph you are really going

64.4 mph

245/80R13 is +1.93 inches (+7.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/70R13245/80R13Difference%
Overall diameter26.50"28.43"+1.93"+7.3%
Section width9.65"9.65"0.00"0.0%
Sidewall height6.75"7.72"+0.96"+14.3%
Circumference83.26"89.33"+6.06"+7.3%
Revolutions per mile760.9709.3−51.6−6.8%

Speedometer difference

If your vehicle came with 245/70R13 and you fit 245/80R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.2 mph+2.2 mph
40 mph42.9 mph+2.9 mph
50 mph53.6 mph+3.6 mph
60 mph64.4 mph+4.4 mph
65 mph69.7 mph+4.7 mph
70 mph75.1 mph+5.1 mph
75 mph80.5 mph+5.5 mph
80 mph85.8 mph+5.8 mph

Each size on its own

Questions

Which is bigger, 245/70R13 or 245/80R13?
245/80R13 is taller by 1.93 inches (28.43" vs 26.50"). 245/70R13 is the same width.
Can I replace 245/70R13 with 245/80R13?
It is not recommended without checking carefully. The diameter difference is +7.3%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 245/80R13 change my speedometer?
When your speedometer reads 60 mph with 245/80R13 fitted (calibrated for 245/70R13), your real speed is 64.4 mph. Your odometer will under-count miles by about 7.3%.
Will 245/80R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.96 inches of ground clearance at the axle.

Other comparisons