What is the diameter difference between 185/60R15 and 195/60R15?

185/60R15 has an overall diameter of 23.74 inches (603 mm). 195/60R15 is 24.21 inches (615 mm). That's a 0.47 inch (12 mm) difference — 195/60R15 is taller.

Will 195/60R15 cause speedometer error on a car fitted with 185/60R15?

Swapping 185/60R15 for 195/60R15 produces a speedometer error of about 2%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.2 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

185/60R15 turns 850 revs per mile. 195/60R15 turns 833 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

185/60R15 has a sidewall of 111 mm (4.37 in). 195/60R15 sidewall is 117 mm (4.61 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 195/60R15 a safe plus-size upgrade from 185/60R15?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 2%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.

Tire size comparison

185/60R15 vs 195/60R15

Overall diameter, sidewall, revs per mile, and speedometer error — 195/60R15 is the taller tire, with a 2% speedo delta when swapping.

185/60R15

23.74in

603 mm overall diameter

195/60R15

24.21in

615 mm overall diameter

Diameter Δ

0.47 in

Speedo error

185/60R15 revs/mi

850

195/60R15 revs/mi

833

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	185/60R15	195/60R15
Section width	185 mm	195 mm
Aspect ratio	60	60
Wheel diameter	15″	15″
Sidewall height	111 mm	117 mm
Overall diameter	23.74 in (603 mm)	24.21 in (615 mm)
Circumference	74.58 in	76.07 in
Revolutions / mile	850	833

Other comparisons for these sizes

175/65R14 vs 185/60R15 185/65R14 vs 195/60R15 185/65R14 vs 185/60R15 185/60R15 vs 205/50R17 195/65R15 vs 195/60R15 195/60R15 vs 205/55R16 195/60R15 vs 215/50R17

FAQ

Frequently asked

What is the diameter difference between 185/60R15 and 195/60R15?: 185/60R15 has an overall diameter of 23.74 inches (603 mm). 195/60R15 is 24.21 inches (615 mm). That's a 0.47 inch (12 mm) difference — 195/60R15 is taller.
Will 195/60R15 cause speedometer error on a car fitted with 185/60R15?: Swapping 185/60R15 for 195/60R15 produces a speedometer error of about 2%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.2 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 185/60R15 turns 850 revs per mile. 195/60R15 turns 833 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 185/60R15 has a sidewall of 111 mm (4.37 in). 195/60R15 sidewall is 117 mm (4.61 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 195/60R15 a safe plus-size upgrade from 185/60R15?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 2%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.