275/65R20 vs 35x12.50R20

35x12.50R20 is 0.9" taller than 275/65R20 (2.7%)

Diameter difference+2.72%diameter 34.07" → 35.00"
275/65R2035x12.50R20
275/65R2035x12.50R20Difference
Overall diameter34.07"35.00"+0.93"
Section width10.83"12.50"+1.67"
Sidewall height7.04"7.50"+0.46"
Circumference107.0"110.0"+2.9"
Revolutions per mile592576−16
Wheel diameter20"20"±0"

Speedometer

ShowsActualDiff
30 mph30.8 mph+0.8
45 mph46.2 mph+1.2
60 mph61.6 mph+1.6
70 mph71.9 mph+1.9
80 mph82.2 mph+2.2

Gear ratio to match

CurrentEquivalent
3.423.51
3.553.65
3.733.83
4.104.21

35x12.50R20 is 0.93" taller than 275/65R20, a +2.72% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.46" (half the diameter change), and the tire needs 0.46" more room above it.

35x12.50R20 is 1.67" wider. On the same wheel offset about half of that, 0.84", moves toward the suspension and half toward the fender.

Both fit a 20" wheel; the sidewall is 0.46" taller on 35x12.50R20.

Details: 275/65R20 in inches · 35x12.50R20 in inches · change sizes in the calculator

FAQ

What is the difference between 275/65R20 and 35x12.50R20?

35x12.50R20 is 0.93" taller (+2.72%) and 1.67" wider than 275/65R20.

Will 35x12.50R20 change my speedometer?

Yes, by +2.72%. When the speedometer shows 60 mph you would be going 61.6 mph.

Can I replace 275/65R20 with 35x12.50R20?

Often yes: the diameter change of +2.7% is within the common 3% guideline. Check the load index, speed rating and clearance.