275/60R20 vs 285/60R20

285/60R20 is 0.5" taller than 275/60R20 (1.4%)

Diameter difference+1.43%diameter 32.99" → 33.46"
275/60R20285/60R20
275/60R20285/60R20Difference
Overall diameter32.99"33.46"+0.47"
Section width10.83"11.22"+0.39"
Sidewall height6.50"6.73"+0.24"
Circumference103.6"105.1"+1.5"
Revolutions per mile611603−9
Wheel diameter20"20"±0"

Speedometer

ShowsActualDiff
30 mph30.4 mph+0.4
45 mph45.6 mph+0.6
60 mph60.9 mph+0.9
70 mph71.0 mph+1.0
80 mph81.1 mph+1.1

Gear ratio to match

CurrentEquivalent
3.423.47
3.553.60
3.733.78
4.104.16

285/60R20 is 0.47" taller than 275/60R20, a +1.43% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.24" (half the diameter change), and the tire needs 0.24" more 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 0.24" taller on 285/60R20.

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

FAQ

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

285/60R20 is 0.47" taller (+1.43%) and 0.39" wider than 275/60R20.

Will 285/60R20 change my speedometer?

Yes, by +1.43%. When the speedometer shows 60 mph you would be going 60.9 mph.

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

Often yes: the diameter change of +1.4% is within the common 3% guideline. Check the load index, speed rating and clearance.