325/65R18 vs 295/70R18

325/65R18 is 0.4" taller than 295/70R18 (1.1%)

Diameter difference−1.08%diameter 34.63" → 34.26"
325/65R18295/70R18
325/65R18295/70R18Difference
Overall diameter34.63"34.26"−0.37"
Section width12.80"11.61"−1.18"
Sidewall height8.32"8.13"−0.19"
Circumference108.8"107.6"−1.2"
Revolutions per mile582589+6
Wheel diameter18"18"±0"

Speedometer

ShowsActualDiff
30 mph29.7 mph−0.3
45 mph44.5 mph−0.5
60 mph59.4 mph−0.6
70 mph69.2 mph−0.8
80 mph79.1 mph−0.9

Gear ratio to match

CurrentEquivalent
3.423.38
3.553.51
3.733.69
4.104.06

295/70R18 is 0.37" shorter than 325/65R18, a −1.08% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.19" (half the diameter change), and the tire needs 0.19" less room above it.

325/65R18 is 1.18" wider. On the same wheel offset about half of that, 0.59", moves toward the suspension and half toward the fender.

Both fit a 18" wheel; the sidewall is 0.19" shorter on 295/70R18.

Details: 325/65R18 in inches · 295/70R18 in inches · change sizes in the calculator

FAQ

What is the difference between 325/65R18 and 295/70R18?

295/70R18 is 0.37" shorter (−1.08%) and 1.18" narrower than 325/65R18.

Will 295/70R18 change my speedometer?

Yes, by −1.08%. When the speedometer shows 60 mph you would be going 59.4 mph.

Can I replace 325/65R18 with 295/70R18?

Often yes: the diameter change of −1.1% is within the common 3% guideline. Check the load index, speed rating and clearance.