TireSizesFinder

155/70R13 vs 145/80R13

145/80R13 is 0.59 in (15.0 mm) taller than 155/70R13, a +2.74% diameter difference. With the speedometer set for 155/70R13, an indicated 60 mph is 61.6 mph on 145/80R13.

Is this a safe swap?

Diameter difference +2.74%: within the ±3% guideline

By overall diameter alone, 145/80R13 falls inside the ±3% range commonly used as a guideline when replacing 155/70R13. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 155/70R13 (21.54 in) vs 145/80R13 (22.13 in)155/70R1321.54 in × 6.10 in145/80R1322.13 in × 5.71 in
Side profile and tread width, drawn to the same scale.
155/70R13 vs 145/80R13 differences
Measurement155/70R13145/80R13Difference% diff
Overall diameter21.54 in (547.2 mm)22.13 in (562.2 mm)+0.59 in (+15.0 mm)+2.74%
Sidewall height4.27 in (108.5 mm)4.57 in (116.0 mm)+0.30 in (+7.5 mm)+6.91%
Section width6.10 in (155.0 mm)5.71 in (145.0 mm)−0.39 in (−10.0 mm)−6.45%
Circumference67.68 in (1,719.1 mm)69.54 in (1,766.2 mm)+1.86 in (+47.1 mm)+2.74%
Revolutions per mile936911−25−2.67%
True speed with the speedometer calibrated for 155/70R13
IndicatedActual on 155/70R13Actual on 145/80R13Difference
30 mph30.0 mph30.8 mph+0.8 mph
60 mph60.0 mph61.6 mph+1.6 mph
75 mph75.0 mph77.1 mph+2.1 mph

Ride-height change: 145/80R13 raises the vehicle by 0.30 in (7.5 mm) at the axle (half the +15.0 mm diameter difference).

145/80R13 is 0.59 in taller than 155/70R13 and 10 mm narrower, a 2.74% difference in overall diameter.

With the speedometer calibrated for 155/70R13, an indicated 60 mph is actually 61.6 mph on 145/80R13, and revolutions per mile change from 936 to 911.

Both sizes mount on 13-inch wheels.

Size pages

Other comparisons with 155/70R13

Other comparisons with 145/80R13

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.