What is the diameter difference between 205/55R16 and 205/50R17?

205/55R16 has an overall diameter of 24.88 inches (632 mm). 205/50R17 is 25.07 inches (637 mm). That's a 0.19 inch (5 mm) difference — 205/50R17 is taller.

Will 205/50R17 cause speedometer error on a car fitted with 205/55R16?

Swapping 205/55R16 for 205/50R17 produces a speedometer error of about 0.8%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 60.5 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

205/55R16 turns 811 revs per mile. 205/50R17 turns 804 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

205/55R16 has a sidewall of 113 mm (4.44 in). 205/50R17 sidewall is 103 mm (4.04 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 205/50R17 a safe plus-size upgrade from 205/55R16?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 0.8%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.

Tire size comparison

205/55R16 vs 205/50R17

Overall diameter, sidewall, revs per mile, and speedometer error — 205/50R17 is the taller tire, with a 0.8% speedo delta when swapping.

205/55R16

24.88in

632 mm overall diameter

205/50R17

25.07in

637 mm overall diameter

Diameter Δ

0.19 in

Speedo error

0.8%

205/55R16 revs/mi

811

205/50R17 revs/mi

804

Within the ±3% overall-diameter band usually considered safe for plus-sizing — speedometer and ABS calibration should stay close to factory.

Full spec

Side by side

Metric	205/55R16	205/50R17
Section width	205 mm	205 mm
Aspect ratio	55	50
Wheel diameter	16″	17″
Sidewall height	113 mm	103 mm
Overall diameter	24.88 in (632 mm)	25.07 in (637 mm)
Circumference	78.16 in	78.76 in
Revolutions / mile	811	804

Other comparisons for these sizes

185/65R14 vs 205/55R16 185/60R15 vs 205/50R17 195/60R15 vs 205/55R16 205/55R16 vs 215/50R17 205/55R16 vs 225/45R18 205/55R16 vs 205/60R16 205/50R17 vs 225/40R19 205/50R17 vs 215/50R17 205/50R17 vs 225/50R17

FAQ

Frequently asked

What is the diameter difference between 205/55R16 and 205/50R17?: 205/55R16 has an overall diameter of 24.88 inches (632 mm). 205/50R17 is 25.07 inches (637 mm). That's a 0.19 inch (5 mm) difference — 205/50R17 is taller.
Will 205/50R17 cause speedometer error on a car fitted with 205/55R16?: Swapping 205/55R16 for 205/50R17 produces a speedometer error of about 0.8%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 60.5 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 205/55R16 turns 811 revs per mile. 205/50R17 turns 804 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 205/55R16 has a sidewall of 113 mm (4.44 in). 205/50R17 sidewall is 103 mm (4.04 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 205/50R17 a safe plus-size upgrade from 205/55R16?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 0.8%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.