285/75R18 vs 295/70R18

285/75R18 is 0.6" taller than 295/70R18 (1.6%)

Diameter difference−1.64%diameter 34.83" → 34.26"
285/75R18295/70R18
285/75R18295/70R18Difference
Overall diameter34.83"34.26"−0.57"
Section width11.22"11.61"+0.39"
Sidewall height8.42"8.13"−0.29"
Circumference109.4"107.6"−1.8"
Revolutions per mile579589+10
Wheel diameter18"18"±0"

Speedometer

ShowsActualDiff
30 mph29.5 mph−0.5
45 mph44.3 mph−0.7
60 mph59.0 mph−1.0
70 mph68.9 mph−1.1
80 mph78.7 mph−1.3

Gear ratio to match

CurrentEquivalent
3.423.36
3.553.49
3.733.67
4.104.03

295/70R18 is 0.57" shorter than 285/75R18, a −1.64% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.29" (half the diameter change), and the tire needs 0.29" less room above it.

295/70R18 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 18" wheel; the sidewall is 0.29" shorter on 295/70R18.

Details: 285/75R18 in inches · 295/70R18 in inches · change sizes in the calculator

FAQ

What is the difference between 285/75R18 and 295/70R18?

295/70R18 is 0.57" shorter (−1.64%) and 0.39" wider than 285/75R18.

Will 295/70R18 change my speedometer?

Yes, by −1.64%. When the speedometer shows 60 mph you would be going 59.0 mph.

Can I replace 285/75R18 with 295/70R18?

Often yes: the diameter change of −1.6% is within the common 3% guideline. Check the load index, speed rating and clearance.