215/45R17 vs 225/45R17 tire size

A 225/45R17 is 0.35 inches (9 mm) taller and 0.39 inches (10 mm) wider than a 215/45R17. Fit them in place of 215/45R17 tires and the speedometer reads low: at 60 mph on it you’re doing 60.9 mph, 1.4% faster, and the vehicle sits 0.18 inches (4 mm) higher.

Sources checked

Dimension215/45R17225/45R17Change
Overall diameter24.62 in (625 mm)24.97 in (634 mm)+0.35 in (+9 mm)
Section width8.46 in (215 mm)8.86 in (225 mm)+0.40 in (+10 mm)
Sidewall height3.81 in (97 mm)3.99 in (101 mm)+0.18 in (+4 mm)
Aspect ratio45%45%
Rim diameter17 in17 in
Circumference77.3 in (1,964 mm)78.5 in (1,993 mm)+1.2 in
Revolutions per mile819808−11
Revolutions per km509502−7

Check another speed or size

Metric, LT and flotation

As printed on the sidewall: 265/70R17, LT285/75R16, 33x12.50R15.

Leave it empty to see one size on its own.

mph

Set for your tire size.

Speed unit

At 60 mph on the speedometer you’re doing

60.9mph

+1.4% · the speedometer reads low

Height
+0.35 in (+9 mm)
Width
+0.39 in (+10 mm)
Ground clearance
+0.18 in (+4 mm)
Each side, same wheel
+0.20 in (+5 mm)

215/45R17 and 225/45R17 side by side

Dimension215/45R17225/45R17Change
Overall diameter24.62 in (625 mm)24.97 in (634 mm)+0.35 in (+9 mm)
Section width8.46 in (215 mm)8.86 in (225 mm)+0.40 in (+10 mm)
Sidewall height3.81 in (97 mm)3.99 in (101 mm)+0.18 in (+4 mm)
Aspect ratio45%45%
Rim diameter17 in17 in
Circumference77.3 in78.5 in+1.2 in
Revolutions per mile819808−11
Revolutions per km509502−7

The working

  1. 215/45R17: sidewall = 215 mm × 45% = 96.8 mm = 3.81 in.
  2. Diameter = rim + 2 × sidewall = 17 + 2 × 3.81 = 24.62 in (625 mm).
  3. Circumference = π × 24.62 = 77.3 in; revolutions per mile = 63,360 ÷ 77.3 = 819.
  4. 225/45R17: sidewall = 225 mm × 45% = 101.3 mm = 3.99 in.
  5. Diameter = rim + 2 × sidewall = 17 + 2 × 3.99 = 24.97 in (634 mm).
  6. Circumference = π × 24.97 = 78.5 in; revolutions per mile = 63,360 ÷ 78.5 = 808.
  7. Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 24.97 ÷ 24.62 = 60.9 mph.
  8. Ground clearance. Half the change in diameter: (24.97 − 24.62) ÷ 2 = +0.18 in.

Speedometer

A 225/45R17 turns 808 times a mile against the 215/45R17’s 819. With a speedometer set for 215/45R17, true speed is what it shows × 24.97 ÷ 24.62:

Speedometer showsTrue speedDifference
25 mph25.4 mph+0.4 mph
35 mph35.5 mph+0.5 mph
45 mph45.6 mph+0.6 mph
55 mph55.8 mph+0.8 mph
65 mph65.9 mph+0.9 mph
75 mph76.1 mph+1.1 mph

Clearance

  • Ground clearance: +0.18 in (+4 mm), half the change in diameter.
  • Top of the tread: +0.18 in (+4 mm), so that much less room under the fender.
  • Each side, on the same wheel: +0.20 in (+5 mm), toward the suspension inside and toward the fender lip outside.

A new wheel with a different width or offset moves the tire again. The sidewall goes from 3.81 to 3.99 inches.

What tire makers publish

Inflated on the maker’s measuring rim; the percentage is against the arithmetic.

TireSize as printedDiameterWidthRevs per mile
Toyo Proxes Sport A/S215/45R1724.6 in (−0.1%)8.4 in843
Toyo Extensa A/S II225/45R1725 in (+0.1%)8.9 in832
Toyo Proxes Sport A/S225/45R1725 in (+0.1%)8.9 in832

Each size on its own

Other comparisons

Questions

Can I fit 225/45R17 tires instead of 215/45R17?

They fit the same 17-inch wheels. A 225/45R17 is 0.35 inches (9 mm) taller and 0.39 inches (10 mm) wider than a 215/45R17, so check three things first: that your wheels are within the 225/45R17’s approved rim width range, which tire makers list for each size; that it clears the fenders and suspension at full lock and full travel; and that its load index meets what your door-jamb placard asks for.

How far off is the speedometer with 225/45R17 tires?

With a speedometer set for 215/45R17, the speedometer reads low: at 60 mph on it you’re doing 60.9 mph, 1.4% faster. The odometer is off the same way: over 1,000 miles driven it shows 985.8.

Does 225/45R17 change the ground clearance?

By +0.18 inches (+4 mm), half the change in diameter, at the axles and at the lowest point under them. On the same wheel, each sidewall sits 0.20 inches further out, inside and outside.

Sources

  1. Bridgestone Americas: Determining tire size: P-metric, Euro-metric, LT-metric, C-type and flotation sizes, and what each number means (checked October 28, 2026)
  2. Toyo Tires: Extensa A/S II sizes and specifications: inflated overall diameter and width, revolutions per mile (checked October 28, 2026)
  3. Toyo Tires: Proxes Sport A/S sizes and specifications: inflated overall diameter and width, revolutions per mile (checked October 28, 2026)
  4. Toyo Tires: Open Country A/T III sizes and specifications: P-metric, LT-metric and flotation sizes, with revolutions per mile (checked October 28, 2026)
  5. Nitto Tire: Trail Grappler M/T sizes and specs: inflated overall diameter and width, LT-metric and flotation sizes (checked October 28, 2026)

Spotted a number that doesn’t match your manual or a source? Tell us; corrections are logged on the sources page.