What is the diameter difference between 295/35R22 and 305/30R22?

295/35R22 has an overall diameter of 30.13 inches (765 mm). 305/30R22 is 29.2 inches (742 mm). That's a 0.93 inch (24 mm) difference — 305/30R22 is shorter.

Will 305/30R22 cause speedometer error on a car fitted with 295/35R22?

Swapping 295/35R22 for 305/30R22 produces a speedometer error of about 3.1%. Your speedometer will read higher than your actual speed — a 60 mph indicated reading is really 58.2 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

295/35R22 turns 669 revs per mile. 305/30R22 turns 691 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

295/35R22 has a sidewall of 103 mm (4.06 in). 305/30R22 sidewall is 92 mm (3.6 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 305/30R22 a safe plus-size upgrade from 295/35R22?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 3.1%. This swap is outside the typical ±3% safe range and may require speedometer recalibration or affect ABS / traction control behaviour.

Tire size comparison

295/35R22 vs 305/30R22

Overall diameter, sidewall, revs per mile, and speedometer error — 295/35R22 is the taller tire, with a 3.1% speedo delta when swapping.

295/35R22

30.13in

765 mm overall diameter

305/30R22

29.2in

742 mm overall diameter

Diameter Δ

0.93 in

Speedo error

3.1%

295/35R22 revs/mi

669

305/30R22 revs/mi

691

Outside the typical ±3% safe plus-size band — you may want speedometer recalibration, and this change can affect ABS or traction control behaviour.

Full spec

Side by side

Metric	295/35R22	305/30R22
Section width	295 mm	305 mm
Aspect ratio	35	30
Wheel diameter	22″	22″
Sidewall height	103 mm	92 mm
Overall diameter	30.13 in (765 mm)	29.2 in (742 mm)
Circumference	94.66 in	91.75 in
Revolutions / mile	669	691

Other comparisons for these sizes

295/35R21 vs 305/30R22 285/30R22 vs 305/30R22 285/35R22 vs 295/35R22 295/30R22 vs 305/30R22 295/30R22 vs 295/35R22 305/30R22 vs 315/30R22 305/30R22 vs 325/30R22

FAQ

Frequently asked

What is the diameter difference between 295/35R22 and 305/30R22?: 295/35R22 has an overall diameter of 30.13 inches (765 mm). 305/30R22 is 29.2 inches (742 mm). That's a 0.93 inch (24 mm) difference — 305/30R22 is shorter.
Will 305/30R22 cause speedometer error on a car fitted with 295/35R22?: Swapping 295/35R22 for 305/30R22 produces a speedometer error of about 3.1%. Your speedometer will read higher than your actual speed — a 60 mph indicated reading is really 58.2 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 295/35R22 turns 669 revs per mile. 305/30R22 turns 691 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 295/35R22 has a sidewall of 103 mm (4.06 in). 305/30R22 sidewall is 92 mm (3.6 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 305/30R22 a safe plus-size upgrade from 295/35R22?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 3.1%. This swap is outside the typical ±3% safe range and may require speedometer recalibration or affect ABS / traction control behaviour.