255/45R19 tire size: 28.04 in tall
Diameter, sidewall, width and revs per mile for 255/45R19, the common sizes within 3% of its diameter, and what each one does to the speedometer.
255/45R19, in short: 28.04 in (712 mm) tall and 255 mm (10.04 in) wide, with a 4.52 in (114.8 mm) sidewall, for a 19-inch wheel. Circumference is 88.08 in, so it turns about 719 times per mile (calculated from the nominal size).
Calculated from the size: sidewall = 255 × 45% = 114.75 mm; diameter = 2 × 4.518 in + 19 in; revs per mile = 63,360 ÷ (π × diameter).
Sizes within 3% of 255/45R19
15 common sizes come within ±3% of 28.04 in: 4 on the same 19-inch wheel, 4 plus-size and 7 minus-size. The last column is what the speedometer shows when the vehicle, set up for 255/45R19, is doing a true 60 mph.
| Size | Fit | Diameter | Difference | Width | Sidewall | Revs/mile (calc.) | Speedometer at a true 60 |
|---|---|---|---|---|---|---|---|
| 255/45R19 | This size | 28.04 in | - | 255 mm | 4.52 in | 719 | 60.0 mph |
| 225/60R17 | Minus 2 | 27.63 in | -1.45% | 225 mm | 5.31 in | 730 | 60.9 mph |
| 235/60R17 | Minus 2 | 28.10 in | +0.24% | 235 mm | 5.55 in | 718 | 59.9 mph |
| 225/65R17 | Minus 2 | 28.52 in | +1.71% | 225 mm | 5.76 in | 707 | 59.0 mph |
| 235/50R18 | Minus 1 | 27.25 in | -2.79% | 235 mm | 4.63 in | 740 | 61.7 mph |
| 225/55R18 | Minus 1 | 27.74 in | -1.04% | 225 mm | 4.87 in | 727 | 60.6 mph |
| 235/55R18 | Minus 1 | 28.18 in | +0.51% | 235 mm | 5.09 in | 716 | 59.7 mph |
| 225/60R18 | Minus 1 | 28.63 in | +2.12% | 225 mm | 5.31 in | 704 | 58.8 mph |
| 235/45R19 | Same wheel | 27.33 in | -2.53% | 235 mm | 4.16 in | 738 | 61.6 mph |
| 245/45R19 | Same wheel | 27.68 in | -1.26% | 245 mm | 4.34 in | 729 | 60.8 mph |
| 235/50R19 | Same wheel | 28.25 in | +0.77% | 235 mm | 4.63 in | 714 | 59.5 mph |
| 225/55R19 | Same wheel | 28.74 in | +2.53% | 225 mm | 4.87 in | 702 | 58.5 mph |
| 245/40R20 | Plus 1 | 27.72 in | -1.14% | 245 mm | 3.86 in | 728 | 60.7 mph |
| 255/40R20 | Plus 1 | 28.03 in | -0.01% | 255 mm | 4.02 in | 719 | 60.0 mph |
| 245/45R20 | Plus 1 | 28.68 in | +2.30% | 245 mm | 4.34 in | 703 | 58.6 mph |
| 255/35R21 | Plus 2 | 28.03 in | -0.03% | 255 mm | 3.51 in | 720 | 60.0 mph |
A taller tire makes the speedometer read low, a shorter one high. Plus-sizing keeps the diameter close by trading sidewall for wheel. Any replacement needs a load index at least as high as the vehicle's tire placard calls for, and a wheel width the tire is approved for.
255/45R19 compared
255/45R19 side by side with 255/40R20 and 255/50R19: dimension by dimension, and what the swap does to the speedometer.
255/45R19 vs 255/40R20
-0.01% diameter| 255/45R19 | 255/40R20 | Difference | |
|---|---|---|---|
| Overall diameter | 28.04 in | 28.03 in | -0.00 in (-0.0%) |
| Section width | 255 mm | 255 mm | +0 mm |
| Sidewall height | 4.52 in | 4.02 in | -0.50 in |
| Wheel diameter | 19 in | 20 in | +1 in |
| Circumference | 88.1 in | 88.1 in | -0.0 in |
| Revs per mile (calc.) | 719 | 719 | +0 |
255/40R20 and 255/45R19 have the same diameter, so the speedometer doesn't change.
255/45R19 vs 255/50R19
+3.58% diameter| 255/45R19 | 255/50R19 | Difference | |
|---|---|---|---|
| Overall diameter | 28.04 in | 29.04 in | +1.00 in (+3.6%) |
| Section width | 255 mm | 255 mm | +0 mm |
| Sidewall height | 4.52 in | 5.02 in | +0.50 in |
| Wheel diameter | 19 in | 19 in | +0 in |
| Circumference | 88.1 in | 91.2 in | +3.2 in |
| Revs per mile (calc.) | 719 | 695 | -25 |
255/50R19 is 3.6% taller than 255/45R19. At a true 60 mph the speedometer shows 57.9 mph (it reads low), and when it shows 60 you're doing 62.1 mph.
Which vehicles come with 255/45R19
Vehicles sold in the US that have 255/45R19 as the standard size on these trims, with the page that lists it. The tire placard on the driver's door edge or post has the size, and the load and inflation, for the exact vehicle.
- Tesla Model Y 2025 model year · Long Range (19-in. standard; 255/40R20 optional)Mavis Tire OE fitment page, 2025 Tesla Model Y Long Range (size flagged standard 'S')
Vehicles mostly picked from Carscoops: 2025 U.S. car sales, full-year top 25 (Car and Driver data, January 2026).
Questions about 255/45R19 tires
How tall is a 255/45R19 tire?
What is 255/45R19 in inches?
How many revolutions per mile does a 255/45R19 tire make?
What size can replace 255/45R19?
255/45R19 vs 255/40R20: what's the difference?
Which vehicles come with 255/45R19 tires?
How these numbers are worked out
- NHTSA: Tire safety, everything rides on it (reading the sidewall and the placard)
- Tire Rack: How do I calculate tire dimensions?
- Jalopnik: What the 3% rule means for your tires (April 2026)
Checked October 2026. Dimensions are nominal, calculated from the size designation. A real tire's diameter, width and revs per mile vary by brand, tread depth, rim width and load, so check the maker's spec sheet.
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