What is the diameter difference between 205/50R17 and 225/50R17?

205/50R17 has an overall diameter of 25.07 inches (637 mm). 225/50R17 is 25.86 inches (657 mm). That's a 0.79 inch (20 mm) difference — 225/50R17 is taller.

Will 225/50R17 cause speedometer error on a car fitted with 205/50R17?

Swapping 205/50R17 for 225/50R17 produces a speedometer error of about 3.1%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.9 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

205/50R17 turns 804 revs per mile. 225/50R17 turns 780 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

205/50R17 has a sidewall of 103 mm (4.04 in). 225/50R17 sidewall is 113 mm (4.43 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 225/50R17 a safe plus-size upgrade from 205/50R17?

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

205/50R17 vs 225/50R17

Overall diameter, sidewall, revs per mile, and speedometer error — 225/50R17 is the taller tire, with a 3.1% speedo delta when swapping.

205/50R17

25.07in

637 mm overall diameter

225/50R17

25.86in

657 mm overall diameter

Diameter Δ

0.79 in

Speedo error

3.1%

205/50R17 revs/mi

804

225/50R17 revs/mi

780

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	205/50R17	225/50R17
Section width	205 mm	225 mm
Aspect ratio	50	50
Wheel diameter	17″	17″
Sidewall height	103 mm	113 mm
Overall diameter	25.07 in (637 mm)	25.86 in (657 mm)
Circumference	78.76 in	81.24 in
Revolutions / mile	804	780

Other comparisons for these sizes

185/60R15 vs 205/50R17 205/55R16 vs 205/50R17 205/50R17 vs 225/40R19 205/50R17 vs 215/50R17 215/55R17 vs 225/50R17 215/50R17 vs 225/50R17 225/50R17 vs 235/45R18 225/50R17 vs 225/45R18 225/50R17 vs 245/40R19 225/50R17 vs 225/45R17

FAQ

Frequently asked

What is the diameter difference between 205/50R17 and 225/50R17?: 205/50R17 has an overall diameter of 25.07 inches (637 mm). 225/50R17 is 25.86 inches (657 mm). That's a 0.79 inch (20 mm) difference — 225/50R17 is taller.
Will 225/50R17 cause speedometer error on a car fitted with 205/50R17?: Swapping 205/50R17 for 225/50R17 produces a speedometer error of about 3.1%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.9 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 205/50R17 turns 804 revs per mile. 225/50R17 turns 780 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 205/50R17 has a sidewall of 103 mm (4.04 in). 225/50R17 sidewall is 113 mm (4.43 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 225/50R17 a safe plus-size upgrade from 205/50R17?: 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.