TireSizeCheck

215/70R16 vs 205/65R16

Fitment assessment

Fitment not determined

Diameter change

−4.9%

Overall diameter changes 4.9%; section width changes -10 mm. Diameter comparison alone cannot confirm fitment. Verify the vehicle maker's approved rim width, tire load and speed ratings, and clearance at full steering lock and suspension compression. Confirm any possible ABS, traction-control, speedometer, and drivetrain effects with the vehicle maker or a qualified tire professional.

New overall diameter

26.49″

was 27.85″

True speed at an indicated 60

57.1 mph

your speedo reads high

Revolutions per mile

761

was 724, +37

Measurement 215/70R16 205/65R16 Change
Overall diameter 27.85″ 26.49″ −1.36″ (−4.9%)
Sidewall height 5.93″ (150.5 mm) 5.25″ (133.3 mm) −17.3 mm
Tread width 215 mm 205 mm −10 mm
Circumference 87.49″ 83.23″ −4.27″
Revs per mile 724 761 +37
Speedometer error baseline −4.9% reads high

Diameter overlay

215/70R16 205/65R16

Speedometer check

With 205/65R16 fitted, when the speedometer shows the indicated speed, your actual speed is:

25 mph shown

23.8 mph actual

35 mph shown

33.3 mph actual

45 mph shown

42.8 mph actual

55 mph shown

52.3 mph actual

65 mph shown

61.8 mph actual

75 mph shown

71.3 mph actual

Common questions

Will 205/65R16 fit instead of 215/70R16?
Overall diameter changes 4.9%; section width changes -10 mm. Diameter comparison alone cannot confirm fitment. Verify the vehicle maker's approved rim width, tire load and speed ratings, and clearance at full steering lock and suspension compression. Confirm any possible ABS, traction-control, speedometer, and drivetrain effects with the vehicle maker or a qualified tire professional. Overall diameter goes from 27.85″ to 26.49″, a change of −4.9%. The rule of thumb most shops use: under 3% is fine, 3 to 5% needs a clearance check, over 5% needs recalibration.
How far off will my speedometer read on 205/65R16?
At an indicated 60 mph you are really doing about 57.1 mph, a −4.9% error. The speedometer reads high, so you are going slower than it shows.
What is the difference in revolutions per mile between 215/70R16 and 205/65R16?
215/70R16 turns about 724 times per mile and 205/65R16 turns about 761, a difference of +37. Your speedometer and odometer both count rotations, so this number is what throws them off.