205/65R15 vs 205/55R16
New overall diameter
24.88″
was 25.49″
True speed at an indicated 60
58.6 mph
speedometer reads high
Revolutions per mile
811
was 791 · +20
Switching from 205/65R15 to 205/55R16? Everything that changes is below — sidewall, tread width, circumference, revolutions per mile and speedometer error at road speeds.
| Measurement | 205/65R15 | 205/55R16 | Change |
|---|---|---|---|
| Overall diameter | 25.49″ | 24.88″ | −0.61″ (−2.4%) |
| Sidewall height | 5.25″ (133.3 mm) | 4.44″ (112.8 mm) | −20.5 mm |
| Tread width | 205 mm | 205 mm | +0 mm |
| Circumference | 80.09″ | 78.16″ | −1.93″ |
| Revs per mile | 791 | 811 | +20 |
| Speedometer error | baseline | −2.4% | reads high |
Diameter overlay
205/65R15 205/55R16
Speedometer check
With 205/55R16 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
24.4 mph actual
35 mph shown
34.2 mph actual
45 mph shown
43.9 mph actual
55 mph shown
53.7 mph actual
65 mph shown
63.4 mph actual
75 mph shown
73.2 mph actual
Common questions
- Will 205/55R16 fit instead of 205/65R15?
- Good fit. Within the 3% rule — overall diameter changes only 2.4%. Speedometer calibration, ABS, traction control and gearing all stay in their intended range. Your speedometer will read higher than your true speed. Overall diameter goes from 25.49″ to 24.88″, a change of −2.4%. As a rule of thumb, under 3% is safe, 3–5% needs a clearance check, and over 5% is not recommended.
- How far off will my speedometer read on 205/55R16?
- At an indicated 60 mph you would actually be travelling about 58.6 mph — a −2.4% error. The speedometer reads high, so you are going slower than it shows.
- What is the difference in revolutions per mile between 205/65R15 and 205/55R16?
- 205/65R15 turns roughly 791 revolutions per mile; 205/55R16 turns roughly 811. That is a change of +20 revolutions per mile, which is what shifts odometer and speedometer readings.