Tire Size Box

295/25R21 vs 295/35R21

295/35R21 compared with 295/25R21

+8.7% diameter, 0.0" width

295/35R21 is 29.13" tall vs 26.81". More than the 3% rule of thumb, so check carefully before switching.

26.8"21" rim2.9"11.6" wide
295/25R21 (solid) compared with 295/35R21 (dashed outline), drawn to scale

With 295/35R21 tires, when your speedometer says 60 mph you are really going

65.2 mph

295/35R21 is +2.32 inches (+8.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/25R21295/35R21Difference%
Overall diameter26.81"29.13"+2.32"+8.7%
Section width11.61"11.61"0.00"0.0%
Sidewall height2.90"4.06"+1.16"+40.0%
Circumference84.22"91.51"+7.30"+8.7%
Revolutions per mile752.3692.4−60.0−8.0%

Speedometer difference

If your vehicle came with 295/25R21 and you fit 295/35R21, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.7 mph+1.7 mph
30 mph32.6 mph+2.6 mph
40 mph43.5 mph+3.5 mph
50 mph54.3 mph+4.3 mph
60 mph65.2 mph+5.2 mph
65 mph70.6 mph+5.6 mph
70 mph76.1 mph+6.1 mph
75 mph81.5 mph+6.5 mph
80 mph86.9 mph+6.9 mph

Each size on its own

Questions

Which is bigger, 295/25R21 or 295/35R21?
295/35R21 is taller by 2.32 inches (29.13" vs 26.81"). 295/25R21 is the same width.
Can I replace 295/25R21 with 295/35R21?
It is not recommended without checking carefully. The diameter difference is +8.7%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 295/35R21 change my speedometer?
When your speedometer reads 60 mph with 295/35R21 fitted (calibrated for 295/25R21), your real speed is 65.2 mph. Your odometer will under-count miles by about 8.7%.
Will 295/35R21 lift my vehicle?
Ride height changes by half the diameter difference: +1.16 inches of ground clearance at the axle.

Other comparisons