195/55R15 vs 205/45R16

Switching from 195/55R15 to 205/45R16 decreases the overall diameter by 4.6 mm (0.8%). That is within the usual ±3% guideline.

195/55R15205/45R16Difference (mm / revs)
Section width195 mm205 mm+10.0
Sidewall height107.2 mm92.2 mm-15.0
Rim diameter381.0 mm406.4 mm+25.4
Overall diameter595.5 mm590.9 mm-4.6
Circumference1,870.8 mm1,856.4 mm-14.4
Revolutions535 per km539 per km+4.0

Speedometer effect

With 205/45R16 fitted on a car calibrated for 195/55R15, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.6 km/h
80 km/h79.4 km/h
100 km/h99.2 km/h
120 km/h119.1 km/h

Smaller tires make the speedometer read higher than the actual speed. Most speedometers also read slightly high from the factory.

Before you change size

195/55R15 dimensions · 205/45R16 dimensions · Open in calculator