245/45R19 tire size

A 245/45R19 tire is 27.7 inches (703 mm) tall and 9.6 inches (245 mm) wide, for a 19-inch wheel. Each sidewall is 4.3 inches (110 mm), 45% of the width, and the tire makes about 729 revolutions a mile.

Sources checked

Dimension245/45R19
Overall diameter27.68 in (703 mm)
Section width9.65 in (245 mm)
Sidewall height4.34 in (110 mm)
Aspect ratio45%
Rim diameter19 in
Circumference87.0 in (2,209 mm)
Revolutions per mile729
Revolutions per km453

Compare 245/45R19 with another 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

57.9mph

−3.5% · the speedometer reads high

Height
−0.96 in (−25 mm)
Width
0.00 in (0 mm)
Ground clearance
−0.48 in (−12 mm)
Each side, same wheel
0.00 in (0 mm)

245/45R19 and 245/40R19 side by side

Dimension245/45R19245/40R19Change
Overall diameter27.68 in (703 mm)26.72 in (679 mm)−0.96 in (−24 mm)
Section width9.65 in (245 mm)9.65 in (245 mm)0.00 in (0 mm)
Sidewall height4.34 in (110 mm)3.86 in (98 mm)−0.48 in (−12 mm)
Aspect ratio45%40%
Rim diameter19 in19 in
Circumference87.0 in83.9 in−3.1 in
Revolutions per mile729755+26
Revolutions per km453469+16

The working

  1. 245/45R19: sidewall = 245 mm × 45% = 110.3 mm = 4.34 in.
  2. Diameter = rim + 2 × sidewall = 19 + 2 × 4.34 = 27.68 in (703 mm).
  3. Circumference = π × 27.68 = 87.0 in; revolutions per mile = 63,360 ÷ 87.0 = 729.
  4. 245/40R19: sidewall = 245 mm × 40% = 98.0 mm = 3.86 in.
  5. Diameter = rim + 2 × sidewall = 19 + 2 × 3.86 = 26.72 in (679 mm).
  6. Circumference = π × 26.72 = 83.9 in; revolutions per mile = 63,360 ÷ 83.9 = 755.
  7. Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 26.72 ÷ 27.68 = 57.9 mph.
  8. Ground clearance. Half the change in diameter: (26.72 − 27.68) ÷ 2 = −0.48 in.

Where the 245/45R19 numbers come from

The section width is 245 mm (9.65 inches), and each sidewall is 45% of it: 110.3 mm, or 4.34 inches. Two sidewalls and the 19-inch rim make 27.68 inches (703 mm).

One turn covers π × 27.68 = 87.0 inches, so the tire turns 729 times a mile and 453 times a kilometer.

What tire makers publish for 245/45R19

Inflated on the maker’s measuring rim. The percentage is the printed diameter against the 27.68 inches worked out above.

TireSize as printedDiameterWidthRevs per mile
Toyo Proxes Sport A/S245/45R1927.7 in (+0.1%)9.6 in751

Other 19-inch sizes against 245/45R19

Each size’s height against 245/45R19, and what a speedometer set for 245/45R19 shows at 60 mph with that size on.

SizeDiameterWidthHeight changeAt 60 mph shown
235/40R1926.4 in9.3 in−4.6%57.2 mph
235/55R1929.2 in9.3 in+5.4%63.2 mph
245/40R19 compared26.7 in9.6 in−3.5%57.9 mph
255/55R1930.0 in10.0 in+8.5%65.1 mph

245/45R19 compared

Every size: the tire size calculator. With the wheels off, the nuts go back on at your vehicle’s lug nut torque.

Questions

What is 245/45R19 in inches?

About 27.7x9.6R19: 27.7 inches tall and 9.6 inches wide on a 19-inch wheel, with 4.3-inch sidewalls. Exactly, 19 + 2 × 245 mm × 0.45 ÷ 25.4 = 27.68 inches.

How many revolutions per mile does a 245/45R19 make?

729 by its diameter: 63,360 inches in a mile ÷ 87.0 inches a turn. Tire makers’ published figures are measured under load, when the tire rolls on a slightly smaller radius, and run 2.8% to 3.3% higher in Toyo’s tables.

Is LT245/45R19 the same size as P245/45R19?

In dimensions, yes: the numbers mean the same in every metric size. The letters mark what the tire is built for, and an LT tire’s load is rated differently, so check the load index and pressure your vehicle needs before swapping one for the other.

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.