255/40R19 in inches

A 255/40R19 tire is 27.0″ tall and 10.0″ wide, and fits a 19″ wheel. In inches it is written 27.0×10.0R19.

Diameter27.03″

Width10.04″

Sidewall4.02″

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

Manufacturer data

How tall 255/40R19 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 21 tires in this size. Their published revolutions per mile work out to 26.2–26.3″ under load (below).

Real 255/40R19 tires measure 27.00–27.10″, against 27.03″ from the size code. They run both taller and shorter than the size code.

Height under load26.2–26.3″

Published revs per mile (768–769) mean the tire rolls like a 26.2–26.3″ tire on the vehicle. Use this for speedometer calibration.

Weight spread24.5–30.6 lb

The lightest (General G-MAX RS, XL) is 6.1 lb lighter per corner than the heaviest (BFGoodrich g-Force COMP-2 A/S PLUS, XL).

21 tires in 255/40R19

Sort by the spec you care about.

	Load					Revs/mi	Source
General G-MAX RSPerformance	XL · 100Y	27.00	24.5	10.0	1,764	769	Spec page
Michelin Pilot Sport 4Performance	XL · 100Y	27.10	24.5	9.0	1,764	769	Spec page
Michelin Pilot Alpin 5Winter	XL · 100H	27.05	25.7	9.5	1,764	769	Spec page
Michelin Primacy All SeasonTouring	SL · 96W	27.00	26.4	8.5	1,565	769	Spec page
Toyo Proxes Sport 2Performance	XL · 100Y	27.00	26.7	9.2	1,764	768	Spec page
General G-MAX AS07Performance	XL · 100W	27.00	27.4	10.0	1,764	769	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 100(Y)	27.10	27.5	8.5	1,764	769	Spec page
Michelin X-Ice Snow+Winter	XL · 100H	27.05	27.8	10.5	1,764	769	Spec page
Michelin Pilot Sport 4Performance	XL · 100W	27.10	27.9	9.5	1,764	769	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 100(Y)	27.10	27.9	9.5	1,764	769	Spec page
Toyo Proxes Sport A/SPerformance	XL · 100Y	27.05	28.0	9.6	1,764	768	Spec page
Michelin CrossClimate2All-season	XL · 100V	27.00	28.1	10.0	1,764	769	Spec page
Toyo Extensa HP IIPerformance	XL · 100W	27.05	28.6	9.7	1,764	768	Spec page
Michelin X-Ice SnowWinter	XL · 100H	27.05	28.6	10.5	1,764	769	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 100Y	27.10	28.7	10.0	1,764	769	Spec page
BFGoodrich g-Force Phenom T/APerformance	XL · 100Y	27.05	28.8	8.5	1,764	769	Spec page
Michelin Pilot Sport 3Performance	XL · 100(Y)	27.10	28.9	9.5	1,764	769	Spec page
Michelin Pilot Sport 3Performance	XL · 100Y	27.10	29.1	9.0	1,764	769	Spec page
Toyo Observe G3-IceWinter	XL · 100T	27.05	30.2	11.3	1,764	768	Spec page
Toyo Celsius SportPerformance	XL · 100W	27.05	30.4	9.9	1,764	768	Spec page
BFGoodrich g-Force COMP-2 A/S PLUSPerformance	XL · 100Y	27.05	30.6	9.0	1,764	769	Spec page

Is 255/40R19 a 27-inch tire?

≈27″

Yes. The size code works out to 27.03″, and the 21 tires here publish 27.00–27.10″, so people call it a 27.

All 27-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 255/40R19	Difference
195/50R19	26.68	-0.35″	-1.3%
325/30R19	26.68	-0.35″	-1.3%
245/40R19	26.72	-0.31″	-1.2%
285/35R19	26.85	-0.18″	-0.7%
225/45R19	26.97	-0.06″	-0.2%
295/35R19	27.13	+0.10″	+0.4%
345/30R19	27.15	+0.12″	+0.4%
235/45R19	27.33	+0.30″	+1.1%
265/40R19	27.35	+0.31″	+1.2%
355/30R19	27.39	+0.35″	+1.3%

How to read 255/40R19

How to read any tire size

How 255/40R19 100Y is printed on the sidewall. It's the most common code among the 21 tires here (8 of them); tires in this size come in other load and speed ratings too.

1255Section width

255 mm across the widest point, or 10.04 inches. Every 255 size

240Aspect ratio

A percentage, not a measurement: the sidewall is 40% as tall as the tire is wide, which is 102.0 mm or 4.02 inches.

3RConstruction

Radial construction.

419Wheel diameter

Mounts on a 19-inch wheel. Approved wheel widths run 8.5″ to 10.0″.

5100Load index

Each tire carries up to 1,764 lb (800 kg) at its maximum pressure.

6YSpeed rating

Rated for up to 186 mph sustained.

XLExtra load

Printed after the size. In this size the XL tires carry up to 1,764 lb each and the standard-load tires up to 1,565 lb, as published.

Specification	Inches	Metric
Overall diameter	27.03	687 mm
Section width	10.04	255 mm
Sidewall height	4.02	102.0 mm
Circumference	84.9	2,157 mm
Revolutions per mile (calculated, unloaded)	746.1	464 per km
Revolutions per mile (published by manufacturers)	768–769	477–478 per km
Approved wheel width	8.5–10.0	216–254 mm

Speedometer error after switching to 255/40R19

Your actual speed– mph

Questions about 255/40R19

What is 255/40R19 in inches?

27.03 inches tall, 10.04 inches wide, on a 19-inch wheel. Written in inches, that is roughly 27.0×10.0R19.

How much does a 255/40R19 tire weigh?

Between 24.5 lb and 30.6 lb for the 21 tires listed here. The lightest is the General G-MAX RS (XL); the heaviest is the BFGoodrich g-Force COMP-2 A/S PLUS (XL).

What wheel width do I need for 255/40R19?

Manufacturers approve 8.5–10.0″ wide wheels for this size.

How many revolutions per mile does a 255/40R19 make?

Published figures run 768–769 revolutions per mile. The calculated figure is 746.1, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 255/40R19 than 225/45R19?

0.06 inches taller on paper (27.03″ vs 26.97″), which raises the axle about 0.03″. Your speedometer will read about 0.2% slow.