275/35R18 vs 295/35R18

295/35R18 is 0.55 in (14.0 mm) taller than 275/35R18, a +2.15% diameter difference. With the speedometer set for 275/35R18, an indicated 60 mph is 61.3 mph on 295/35R18.

Is this a safe swap?

Diameter difference +2.15%: within the ±3% guideline

By overall diameter alone, 295/35R18 falls inside the ±3% range commonly used as a guideline when replacing 275/35R18. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

275/35R18 vs 295/35R18 differences
Measurement	275/35R18	295/35R18	Difference	% diff
Overall diameter	25.58 in (649.7 mm)	26.13 in (663.7 mm)	+0.55 in (+14.0 mm)	+2.15%
Sidewall height	3.79 in (96.3 mm)	4.06 in (103.3 mm)	+0.28 in (+7.0 mm)	+7.27%
Section width	10.83 in (275.0 mm)	11.61 in (295.0 mm)	+0.79 in (+20.0 mm)	+7.27%
Circumference	80.36 in (2,041.1 mm)	82.09 in (2,085.1 mm)	+1.73 in (+44.0 mm)	+2.15%
Revolutions per mile	788	772	−17	−2.11%

True speed with the speedometer calibrated for 275/35R18
Indicated	Actual on 275/35R18	Actual on 295/35R18	Difference
30 mph	30.0 mph	30.6 mph	+0.6 mph
60 mph	60.0 mph	61.3 mph	+1.3 mph
75 mph	75.0 mph	76.6 mph	+1.6 mph

Ride-height change: 295/35R18 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

295/35R18 is 0.55 in taller than 275/35R18 and 20 mm wider, a 2.15% difference in overall diameter.

With the speedometer calibrated for 275/35R18, an indicated 60 mph is actually 61.3 mph on 295/35R18, and revolutions per mile change from 788 to 772.

Both sizes mount on 18-inch wheels.

Size pages

Other comparisons with 275/35R18

Other comparisons with 295/35R18

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.