205/55R16 Tire Size in Inches

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

205/55R16
24.9" tall × 8.1" wide
On a 16-inch wheel · roughly 24.9x8.1R16 in flotation sizing
MeasurementInchesMillimetres
Overall diameter24.88632
Section width8.07205
Sidewall height4.44112.8
Wheel diameter16406
Circumference78.21985
Revolutions per mile811 (504 per km)

What 205/55R16 means

205 is the section width in millimetres (8.1 in). 55 is the aspect ratio: the sidewall is 55% as tall as the tire is wide, which works out to 112.8 mm or 4.4 in. R16 is a radial tire for a 16-inch wheel.

Overall diameter is the wheel plus two sidewalls: 16 + 2 × 4.44 = 24.9 inches. These are the nominal dimensions every maker builds to; a real 205/55R16 can measure a few tenths of an inch differently by model and inflation.

Closest equivalent sizes

Common sizes within the usual 3% of 205/55R16's overall diameter. Confirm load index, speed rating and rim width before swapping.

SizeDiameterWidthChangeSpeedometer at 60
225/50R16 24.9 in 8.9 in -0.1% really 60.0 mph
225/45R17 new wheels 25.0 in 8.9 in +0.4% really 60.2 mph
195/65R15 new wheels 25.0 in 7.7 in +0.4% really 60.2 mph
195/70R14 new wheels 24.7 in 7.7 in -0.5% really 59.7 mph
255/35R18 new wheels 25.0 in 10.0 in +0.6% really 60.4 mph
255/40R17 new wheels 25.0 in 10.0 in +0.6% really 60.4 mph

Speedometer if you switch to 225/50R16

Your speedometer stays calibrated for 205/55R16. 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 mph64.9 mph
75 mph74.9 mph
Compare 205/55R16 with any size →

Shop 205/55R16 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 205/55R16 tire is 24.9 inches (632 mm) tall overall. That is the 16-inch wheel plus two sidewalls of 4.4 inches each (55% of the 205 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 205 mm, or 8.1 inches, measured sidewall to sidewall on the recommended rim width. The tread itself is narrower than that. In flotation sizing, 205/55R16 is roughly a 24.9x8.1R16.

225/50R16 is the closest common size, at -0.1% overall diameter (24.9 in against 24.9 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 811 revolutions per mile (504 per kilometre), from its 24.9-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 16-inch sizes

195/55R16 195/60R16 195/65R16 205/50R16 205/60R16 205/65R16 215/55R16 215/60R16 215/65R16 215/70R16 215/85R16 225/50R16 225/55R16 225/60R16 225/65R16 225/70R16 225/75R16 235/60R16 235/65R16 235/70R16 235/75R16 235/85R16 245/70R16 245/75R16 255/65R16 255/70R16 265/70R16 265/75R16 285/75R16 205/45R16 255/85R16 275/70R16 305/70R16 315/75R16