245/35R21 vs 295/25R22

Q: Can I replace 245/35R21 with 295/25R22?

295/25R22 is a safe swap for 245/35R21 by the usual ±3% rule: the diameter differs by +0.20%.

295/25R22 is a safe swap for 245/35R21 by the usual ±3% rule: the diameter differs by +0.20%.

245/35R21 27.75" · 295/25R22 27.81" · drawn to scale

Side by side

	245/35R21	295/25R22	Difference
Overall diameter	27.75"	27.81"	+0.06" (+0.20%)
Section width	245 mm	295 mm	+50 mm
Sidewall	3.38"	2.90"	-0.47"
Rim	21"	22"	+1"
Circumference	87.2"	87.4"	+0.2"
Revs per mile	727	725	-1
Ride height	—	—	+0.03"
Speedometer reads 60 mph	60.0	60.1	+0.1 mph

Speedometer and odometer

With 295/25R22 on a car calibrated for 245/35R21, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.

Speedo shows	Actual speed
30 mph	30.1 mph
45 mph	45.1 mph
60 mph	60.1 mph
70 mph	70.1 mph
80 mph	80.2 mph

Other sizes close to 245/35R21

Questions

Can I replace 245/35R21 with 295/25R22?

295/25R22 is a safe swap for 245/35R21 by the usual ±3% rule: the diameter differs by +0.20%.

What's the difference between 245/35R21 and 295/25R22?

295/25R22 is 0.06" taller and 50 mm wider; the sidewall is -0.47". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 295/25R22 fit on 245/35R21 wheels?

No — 245/35R21 needs a 21" wheel and 295/25R22 a 22" wheel. This is a plus/minus-size swap that changes wheels too.