205/65R15 vs 205/70R15
Side-by-side comparison of overall diameter, sidewall height, speedometer error, and ride-height change.
Not recommended — Exceeds the 3% diameter limit — speedometer error and ABS/TPMS issues likely.
To scale
205/65R15
- Section width
- 205 mm
- Aspect ratio
- 65%
- Rim diameter
- 15"
- Sidewall
- 133.3 mm
- Overall diameter
- 647.5 mm
- Circumference
- 2034 mm
- Revs / mile
- 791
- Revs / km
- 492
205/70R15
- Section width
- 205 mm
- Aspect ratio
- 70%
- Rim diameter
- 15"
- Sidewall
- 143.5 mm
- Overall diameter
- 668.0 mm
- Circumference
- 2099 mm
- Revs / mile
- 767
- Revs / km
- 477
Difference
- Overall diameter
- +20.5 mm (+3.17%)
- Sidewall height
- +10.3 mm
- Tread width
- +0 mm
- Ride height (axle)
- +10.3 mm
- Speedometer error
- +3.17%
- At indicated 60 mph
- actual 61.9 mph
- At indicated 100 km/h
- actual 103.2 km/h
Will 205/70R15 fit instead of 205/65R15?
The overall diameter changes by 3.17%. Most manufacturers consider a swap acceptable when the difference stays under 3% — beyond that, you may see speedometer error, ABS/TPMS warnings, or wheel-well clearance problems. This page only covers the math; your vehicle's wheel arches, suspension geometry, and load rating still matter.
What the numbers mean
- Overall diameter — outside-to-outside height of the tire. Affects ride height, gearing, and speedometer calibration.
- Sidewall height — rubber from rim edge to tread. Lower sidewall gives sharper steering response but a harsher ride.
- Speedometer error — how far off your indicated speed will be after the swap. Positive means the speedo under-reads (actual speed is higher than shown).