275/65R20 vs 285/60R20

275/65R20 is 0.6" taller than 285/60R20 (1.8%)

Diameter difference−1.79%diameter 34.07" → 33.46"
275/65R20285/60R20
275/65R20285/60R20Difference
Overall diameter34.07"33.46"−0.61"
Section width10.83"11.22"+0.39"
Sidewall height7.04"6.73"−0.31"
Circumference107.0"105.1"−1.9"
Revolutions per mile592603+11
Wheel diameter20"20"±0"

Speedometer

ShowsActualDiff
30 mph29.5 mph−0.5
45 mph44.2 mph−0.8
60 mph58.9 mph−1.1
70 mph68.7 mph−1.3
80 mph78.6 mph−1.4

Gear ratio to match

CurrentEquivalent
3.423.36
3.553.49
3.733.66
4.104.03

285/60R20 is 0.61" shorter than 275/65R20, a −1.79% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.31" (half the diameter change), and the tire needs 0.31" less room above it.

285/60R20 is 0.39" wider. On the same wheel offset about half of that, 0.20", moves toward the suspension and half toward the fender.

Both fit a 20" wheel; the sidewall is 0.31" shorter on 285/60R20.

Details: 275/65R20 in inches · 285/60R20 in inches · change sizes in the calculator

FAQ

What is the difference between 275/65R20 and 285/60R20?

285/60R20 is 0.61" shorter (−1.79%) and 0.39" wider than 275/65R20.

Will 285/60R20 change my speedometer?

Yes, by −1.79%. When the speedometer shows 60 mph you would be going 58.9 mph.

Can I replace 275/65R20 with 285/60R20?

Often yes: the diameter change of −1.8% is within the common 3% guideline. Check the load index, speed rating and clearance.