305/70R16 vs 285/75R16

285/75R16 is 0.0" taller than 305/70R16 (0.1%)

Diameter difference+0.06%diameter 32.81" → 32.83"
305/70R16285/75R16
305/70R16285/75R16Difference
Overall diameter32.81"32.83"+0.02"
Section width12.01"11.22"−0.79"
Sidewall height8.41"8.42"+0.01"
Circumference103.1"103.1"+0.1"
Revolutions per mile615614−0
Wheel diameter16"16"±0"

Speedometer

ShowsActualDiff
30 mph30.0 mph+0.0
45 mph45.0 mph+0.0
60 mph60.0 mph+0.0
70 mph70.0 mph+0.0
80 mph80.0 mph+0.0

Gear ratio to match

CurrentEquivalent
3.423.42
3.553.55
3.733.73
4.104.10

285/75R16 is 0.02" taller than 305/70R16, a +0.06% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.01" (half the diameter change), and the tire needs 0.01" more room above it.

305/70R16 is 0.79" wider. On the same wheel offset about half of that, 0.39", moves toward the suspension and half toward the fender.

Both fit a 16" wheel; the sidewall is 0.01" taller on 285/75R16.

Details: 305/70R16 in inches · 285/75R16 in inches · change sizes in the calculator

FAQ

What is the difference between 305/70R16 and 285/75R16?

285/75R16 is 0.02" taller (+0.06%) and 0.79" narrower than 305/70R16.

Will 285/75R16 change my speedometer?

Yes, by +0.06%. When the speedometer shows 60 mph you would be going 60.0 mph.

Can I replace 305/70R16 with 285/75R16?

Often yes: the diameter change of +0.1% is within the common 3% guideline. Check the load index, speed rating and clearance.