195/45R15 in inches

A 195/45R15 tire is 21.9″ tall and 7.7″ wide, and fits a 15″ wheel. In inches it is written 21.9×7.7R15.

Diameter21.91″

Width7.68″

Sidewall3.45″

Drawn to scale. Nominal dimensions calculated from the size code.

Manufacturer data

How tall 195/45R15 tires really are

Heights published by Toyo for the one tire in this size. Their published revolutions per mile work out to 21.3″ under load (below).

The one tire listed, the Toyo Extensa HP II, measures 21.93″: 0.02″ taller than the size code's 21.91″.

Height under load21.3″

Published revs per mile (947) mean the tire rolls like a 21.3″ tire on the vehicle. Use this for speedometer calibration.

1 tire in 195/45R15

Sort by the spec you care about.

	Load					Revs/mi	Source
Toyo Extensa HP IIPerformance	SL · 78V	21.93	14.8	8.9	937	947	Spec page

Is 195/45R15 a 22-inch tire?

≈22″

Yes. The size code works out to 21.91″, and the 1 tire here publishes 21.93″, so people call it a 22.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 195/45R15	Difference
195/50R15	22.68	+0.77″	+3.5%
245/40R15	22.72	+0.81″	+3.7%
185/60R14	22.74	+0.83″	+3.8%
195/45R16	22.91	+1.00″	+4.6%
175/65R14	22.96	+1.05″	+4.8%
225/45R15	22.97	+1.06″	+4.9%
185/55R15	23.01	+1.10″	+5.0%
205/50R15	23.07	+1.16″	+5.3%
195/55R15	23.44	+1.54″	+7.0%
185/60R15	23.74	+1.83″	+8.4%

How to read 195/45R15

How to read any tire size

How 195/45R15 78V is printed on the sidewall. It's the most common code among the 1 tire here; tires in this size come in other load and speed ratings too.

1195Section width

195 mm across the widest point, or 7.68 inches. Every 195 size

245Aspect ratio

A percentage, not a measurement: the sidewall is 45% as tall as the tire is wide, which is 87.8 mm or 3.45 inches.

3RConstruction

Radial construction.

415Wheel diameter

Mounts on a 15-inch wheel. Approved wheel widths run 6.0″ to 7.5″.

578Load index

Each tire carries up to 937 lb (425 kg) at its maximum pressure.

6VSpeed rating

Rated for up to 149 mph sustained.

Specification	Inches	Metric
Overall diameter	21.91	557 mm
Section width	7.68	195 mm
Sidewall height	3.45	87.8 mm
Circumference	68.8	1,748 mm
Revolutions per mile (calculated, unloaded)	920.5	572 per km
Revolutions per mile (published by manufacturers)	947	588 per km
Approved wheel width	6.0–7.5	152–191 mm

Speedometer error after switching to 195/45R15

Your actual speed– mph

Questions about 195/45R15

What is 195/45R15 in inches?

21.91 inches tall, 7.68 inches wide, on a 15-inch wheel. Written in inches, that is roughly 21.9×7.7R15.

What wheel width do I need for 195/45R15?

Manufacturers approve 6.0–7.5″ wide wheels for this size.

How many revolutions per mile does a 195/45R15 make?

Published figures run 947 revolutions per mile. The calculated figure is 920.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.