Tire size difference in inches · Plus-one wheel size

225/75R15 vs 235/70R16

235/70R16 is 0.67 in (16.9 mm, 2.35%) taller than 225/75R15. Section width 0.39 in wider. Sidewall 0.17 in shorter. At an indicated 60 mph you'd be doing about 61.41 mph.

When replacing 225/75R15 with 235/70R16

Overall diameter
28.29 → 28.95 in
+0.67 in (+16.9 mm), +2.35%
Section width
8.86 → 9.25 in
+0.39 in (+10.0 mm)
Sidewall height
6.64 → 6.48 in
-0.17 in (-4.3 mm), -2.52%
Ride height
+0.33 in
+8.5 mm, half the diameter change
Dash reads 60 mph
61.41 mph
+1.41 mph actual vs indicated
Revolutions per mile
713 → 697
-2.30%, nominal

Each value is rounded on its own, so a change can differ by 0.01 in from the difference between the rounded sizes.

Open this comparison in the interactive calculator

Vehicle compatibility not checked. Diameter difference within 3%. These results compare nominal dimensions. They do not confirm vehicle fitment. Actual clearance varies by tire model, approved rim width, wheel construction, suspension, alignment, body tolerances, steering angle, load, and brake geometry. Verify load and speed ratings and physically test-fit the complete setup before driving.

Tire dimensions only. Wheel width and offset are not assumed on this page, so fender-side and suspension-side position changes are not calculated. Enter your wheel specifications in the calculator for those estimates. How we calculate

What changes from 225/75R15 to 235/70R16

  • Speedometer: at an indicated 60 mph you're actually doing about 61.41 mph, and about 71.65 mph at an indicated 70 mph.
  • Odometer: for every 10,000 miles it shows, you'll have driven about 10,235 miles, 235 more than shown.
  • Engine speed: wheel revolutions per mile go from 713 to 697, so at the same road speed the engine turns about 2.30% slower in any given gear.
  • Width: 235/70R16 is 0.39 in (10.0 mm) wider. Centered in the same place, each sidewall moves about 0.20 in (5.0 mm) outward; wheel width and offset decide the real position.
  • 235/70R16 needs 16 in wheels; it will not mount on 15 in wheels. This is a plus-one size change. On the larger wheel the sidewall is 0.17 in (4.3 mm) shorter. A shorter sidewall generally gives a firmer ride over sharp bumps and leaves less rubber protecting the rim.
  • The profile moves from very tall (75 series) to tall (70 series).
  • The 2.35% diameter change is above 2%, enough to consider speedometer recalibration. Anti-lock brake, traction and stability control systems also use wheel-speed signals, so check the vehicle maker's guidance for this size.
  • For scale, the 0.67 in diameter change is more than the roughly 0.5 in a tire loses as its tread wears from a typical new 10/32 in to the 2/32 in wear bars. This swap changes the speedometer reading more than a full tread's wear does.

Going from 235/70R16 to 225/75R15 instead: 2.30% shorter; an indicated 60 mph is about 58.62 mph. Open 235/70R16 to 225/75R15 in the calculator

How the setup changes

Proposed 235/70R16 is 0.67 in taller overall.

Current 225/75R15 · dashedProposed 235/70R16 · solid

Shared center and scale. Circles compare diameter and rim size, not loaded ride height.

Speedometer

Indicated vs actual

Dash readsEstimated speed
30.00 mph30.71 mph
60.00 mph61.41 mph
70.00 mph71.65 mph

Assumes the speedometer was accurate with the current tires. Uses diameter ratio.

Detailed comparison

Changes are proposed minus current. Nominal rev/mile uses geometric circumference, not measured rolling circumference. Values round independently; rounded columns may not subtract exactly. Wheel specifications retain industry notation.

Detailed tire and wheel measurements
Measurement225/75R15235/70R16Change
Tire size225/75R15235/70R16—
Nominal section width8.86 in (225.0 mm)9.25 in (235.0 mm)+0.39 in (+10.0 mm)
Rim diameter15 in16 in+1.00 in (+25.4 mm)
Overall diameter28.29 in (718.5 mm)28.95 in (735.4 mm)+0.67 in (+16.9 mm)
Radial sidewall estimate6.64 in (168.8 mm)6.48 in (164.5 mm)-0.17 in (-4.3 mm)
Geometric circumference88.87 in (2,257.2 mm)90.96 in (2,310.3 mm)+2.09 in (+53.1 mm)
Revolutions per mile713 (nominal)697 (nominal)-16
Diameter change——+2.35%
Ride-height estimate——+0.33 in (+8.5 mm)

Physical checks

  • Approved rim-width range for the exact tire model.
  • Load index and speed rating equal to or greater than vehicle requirements.
  • Brake-caliper, hub, and wheel-fastener compatibility.
  • Fender, liner, suspension, and full-lock steering clearance.
  • Clearance at full compression and under expected load.
  • Alignment, tire pressure, and manufacturer guidance.
  • Professional inspection when variance or clearance is uncertain.

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Review record

Automated dimensional check against the FitMyTires publication policy (v1) on August 19, 2026. The check covers size data and calculations, not vehicle fitment. Read the editorial and corrections policy.

Methodology and docs