245/40R19 tire size

A 245/40R19 tire is 26.7 inches (679 mm) tall and 9.6 inches (245 mm) wide, for a 19-inch wheel. Each sidewall is 3.9 inches (98 mm), 40% of the width, and the tire makes about 755 revolutions a mile.

Sources checked

Dimension245/40R19
Overall diameter26.72 in (679 mm)
Section width9.65 in (245 mm)
Sidewall height3.86 in (98 mm)
Aspect ratio40%
Rim diameter19 in
Circumference83.9 in (2,132 mm)
Revolutions per mile755
Revolutions per km469

Compare 245/40R19 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

62.2mph

+3.6% · the speedometer reads low

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)

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

Dimension245/40R19245/45R19Change
Overall diameter26.72 in (679 mm)27.68 in (703 mm)+0.96 in (+24 mm)
Section width9.65 in (245 mm)9.65 in (245 mm)0.00 in (0 mm)
Sidewall height3.86 in (98 mm)4.34 in (110 mm)+0.48 in (+12 mm)
Aspect ratio40%45%
Rim diameter19 in19 in
Circumference83.9 in87.0 in+3.1 in
Revolutions per mile755729−26
Revolutions per km469453−16

The working

  1. 245/40R19: sidewall = 245 mm × 40% = 98.0 mm = 3.86 in.
  2. Diameter = rim + 2 × sidewall = 19 + 2 × 3.86 = 26.72 in (679 mm).
  3. Circumference = π × 26.72 = 83.9 in; revolutions per mile = 63,360 ÷ 83.9 = 755.
  4. 245/45R19: sidewall = 245 mm × 45% = 110.3 mm = 4.34 in.
  5. Diameter = rim + 2 × sidewall = 19 + 2 × 4.34 = 27.68 in (703 mm).
  6. Circumference = π × 27.68 = 87.0 in; revolutions per mile = 63,360 ÷ 87.0 = 729.
  7. Speedometer. True speed = what it shows × new diameter ÷ old = 60 × 27.68 ÷ 26.72 = 62.2 mph.
  8. Ground clearance. Half the change in diameter: (27.68 − 26.72) ÷ 2 = +0.48 in.

Where the 245/40R19 numbers come from

The section width is 245 mm (9.65 inches), and each sidewall is 40% of it: 98.0 mm, or 3.86 inches. Two sidewalls and the 19-inch rim make 26.72 inches (679 mm).

One turn covers π × 26.72 = 83.9 inches, so the tire turns 755 times a mile and 469 times a kilometer.

What tire makers publish for 245/40R19

Inflated on the maker’s measuring rim. The percentage is the printed diameter against the 26.72 inches worked out above.

TireSize as printedDiameterWidthRevs per mile
Toyo Proxes Sport A/S245/40R1926.7 in (−0.1%)9.8 in777

Other 19-inch sizes against 245/40R19

Each size’s height against 245/40R19, and what a speedometer set for 245/40R19 shows at 60 mph with that size on.

SizeDiameterWidthHeight changeAt 60 mph shown
235/40R19 compared26.4 in9.3 in−1.2%59.3 mph
235/55R1929.2 in9.3 in+9.2%65.5 mph
245/45R19 compared27.7 in9.6 in+3.6%62.2 mph
255/55R1930.0 in10.0 in+12.5%67.5 mph

245/40R19 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 245/40R19 in inches?

About 26.7x9.6R19: 26.7 inches tall and 9.6 inches wide on a 19-inch wheel, with 3.9-inch sidewalls. Exactly, 19 + 2 × 245 mm × 0.40 ÷ 25.4 = 26.72 inches.

How many revolutions per mile does a 245/40R19 make?

755 by its diameter: 63,360 inches in a mile ÷ 83.9 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 LT245/40R19 the same size as P245/40R19?

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.