195/65R15 Tire Size in Inches

Diameter, width, sidewall and the closest equivalent sizes, computed from the size code.

195/65R15
25.0" tall × 7.7" wide
On a 15-inch wheel · roughly 25.0x7.7R15 in flotation sizing
MeasurementInchesMillimetres
Overall diameter24.98635
Section width7.68195
Sidewall height4.99126.8
Wheel diameter15381
Circumference78.51993
Revolutions per mile807 (502 per km)

What 195/65R15 means

195 is the section width in millimetres (7.7 in). 65 is the aspect ratio: the sidewall is 65% as tall as the tire is wide, which works out to 126.8 mm or 5.0 in. R15 is a radial tire for a 15-inch wheel.

Overall diameter is the wheel plus two sidewalls: 15 + 2 × 4.99 = 25.0 inches. These are the nominal dimensions every maker builds to; a real 195/65R15 can measure a few tenths of an inch differently by model and inflation.

Closest equivalent sizes

Common sizes within the usual 3% of 195/65R15's overall diameter. Confirm load index, speed rating and rim width before swapping.

SizeDiameterWidthChangeSpeedometer at 60
225/45R17 new wheels 25.0 in 8.9 in -0.0% really 60.0 mph
255/35R18 new wheels 25.0 in 10.0 in +0.2% really 60.1 mph
255/40R17 new wheels 25.0 in 10.0 in +0.2% really 60.1 mph
205/50R17 new wheels 25.1 in 8.1 in +0.4% really 60.2 mph
205/55R16 new wheels 24.9 in 8.1 in -0.4% really 59.8 mph
225/40R18 new wheels 25.1 in 8.9 in +0.4% really 60.3 mph

Speedometer if you switch to 225/45R17

Your speedometer stays calibrated for 195/65R15. With a shorter tire you travel slower than it shows.

Speedometer readsTrue speed
30 mph30.0 mph
45 mph45.0 mph
55 mph55.0 mph
65 mph65.0 mph
75 mph75.0 mph
Compare 195/65R15 with any size →

Shop 195/65R15 tires

Check the load index and speed rating on your door-jamb placard before you buy, especially for LT tires used for towing.

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Frequently Asked Questions

A 195/65R15 tire is 25.0 inches (635 mm) tall overall. That is the 15-inch wheel plus two sidewalls of 5.0 inches each (65% of the 195 mm section width). Expect a real tire to measure within a few tenths of an inch of this, depending on the model and inflation.

The section width is 195 mm, or 7.7 inches, measured sidewall to sidewall on the recommended rim width. The tread itself is narrower than that. In flotation sizing, 195/65R15 is roughly a 25.0x7.7R15.

225/45R17 is the closest common size, at -0.0% overall diameter (25.0 in against 25.0 in). Most makers treat about 3% as the limit for a swap without speedometer or clearance problems, but always confirm load index, speed rating and wheel width before changing size.

About 807 revolutions per mile (502 per kilometre), from its 25.0-inch rolling diameter. Real-world figures run slightly higher because a loaded tire squats. This number is what your speedometer and odometer are calibrated against.

Last updated: October 2, 2026

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Other 15-inch sizes

175/65R15 185/55R15 185/60R15 185/65R15 195/55R15 195/60R15 205/60R15 205/65R15 205/70R15 205/75R15 215/60R15 215/65R15 215/70R15 215/75R15 225/60R15 225/70R15 225/75R15 235/70R15 235/75R15