33x12.50R15 tire size in inches
A 33x12.50R15 tire is 32.52 inches tall and 12.52 inches wide on a 15-inch rim. These are nominal dimensions from the official sizing formula.
| Dimension | 33x12.50R15 | This size vs yours | |
|---|---|---|---|
| Overall diameter UN R54 Annex 5 Table B | 32.52 in 826.0 mm | ||
| Section width UN R54 Annex 5 Table B | 12.52 in 318.0 mm | ||
| Sidewall height UN R54 §6.1.5.1 | 8.76 in 222.5 mm | ||
| Rim diameter Marked on the tire | 15 in | ||
| Circumference From diameter | 102.16 in | ||
| Revolutions per mile From diameter | 620 | ||
| Allowed real diameter UN R54 §6.1.5, Table B | 31.99–33.75 in |
Is 33x12.50R15 a 33-inch tire?
Yes. At 32.52 inches tall, 33x12.50R15 is commonly called a 33-inch tire. Inch-class names round to the nearest inch; the true nominal height is 32.52 in, and a new tire may legally measure between 31.99 and 33.75 in.
Speedometer change
Example: if your speedometer is calibrated for 275/55R20 and you fit 33x12.50R15, the tire is +1.9% in diameter, so your true speed differs from the reading as shown below. Enter your current size above to see your own figures.
| Reading | True speed | Difference |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 mph |
| 45 mph | 45.9 mph | +0.9 mph |
| 55 mph | 56.1 mph | +1.1 mph |
| 60 mph | 61.1 mph | +1.1 mph |
| 70 mph | 71.3 mph | +1.3 mph |
| 80 mph | 81.5 mph | +1.5 mph |
Sizes within 3% of 33x12.50R15
These sizes are within 3% of the diameter of 33x12.50R15. The 3% figure is a rule of thumb, not a regulation and not a fitment check: wheel width, offset, suspension and body clearance decide what fits. See changing tire size.
| Size | Diameter (in) | Width (in) | Change | ±3% | Ride height (in) |
|---|---|---|---|---|---|
| 265/65R18 | 31.56 | 10.43 | −2.9% | −0.48 | |
| 265/70R17 | 31.61 | 10.43 | −2.8% | −0.46 | |
| 265/75R16 | 31.65 | 10.43 | −2.7% | −0.44 | |
| 235/85R16 | 31.73 | 9.25 | −2.4% | −0.40 | |
| 275/55R20 | 31.91 | 10.83 | −1.9% | −0.31 | |
| 255/75R17 | 32.06 | 10.04 | −1.4% | −0.23 | |
| 275/65R18 | 32.07 | 10.83 | −1.4% | −0.22 | |
| 275/70R17 | 32.16 | 10.83 | −1.1% | −0.18 | |
| 285/55R20 | 32.34 | 11.22 | −0.5% | −0.09 | |
| 265/60R20 | 32.52 | 10.43 | 0.0% | 0.00 | |
| 33x12.50R15 | 32.52 | 12.52 | — | — | |
| 285/65R18 | 32.59 | 11.22 | +0.2% | +0.03 | |
| 265/70R18 | 32.61 | 10.43 | +0.3% | +0.04 | |
| 285/70R17 | 32.71 | 11.22 | +0.6% | +0.09 | |
| 295/55R20 | 32.78 | 11.61 | +0.8% | +0.13 | |
| 305/70R16 | 32.81 | 12.01 | +0.9% | +0.15 | |
| 285/75R16 | 32.83 | 11.22 | +1.0% | +0.16 | |
| 275/60R20 | 32.99 | 10.83 | +1.5% | +0.24 | |
| 33x12.50R17 | 33.00 | 12.50 | +1.5% | +0.24 | |
| 255/85R16 | 33.07 | 10.04 | +1.7% | +0.27 | |
| 275/70R18 | 33.16 | 10.83 | +2.0% | +0.32 | |
| 305/55R20 | 33.21 | 12.01 | +2.1% | +0.34 | |
| 295/70R17 | 33.26 | 11.61 | +2.3% | +0.37 | |
| 295/75R16 | 33.42 | 11.61 | +2.8% | +0.45 | |
| 285/60R20 | 33.46 | 11.22 | +2.9% | +0.47 |
Metric equivalent of 33x12.50R15
These metric sizes are within 2% of the diameter of 33x12.50R15. Same rim first.
| Metric size | Diameter (in) | Change | Width (in) | Rim (in) |
|---|---|---|---|---|
| 265/60R20 | 32.52 | 0.0% | 10.43 | 20 |
| 285/65R18 | 32.59 | +0.2% | 11.22 | 18 |
| 265/70R18 | 32.61 | +0.3% | 10.43 | 18 |
| 305/65R17 | 32.61 | +0.3% | 12.01 | 17 |
| 305/35R24 | 32.41 | −0.4% | 12.01 | 24 |
| 265/75R17 | 32.65 | +0.4% | 10.43 | 17 |
How 33x12.50R15 is calculated
UN R54 lists 33x12.50R15LT in its table of US high flotation sizes at 826 mm (32.52 in) tall and 318 mm (12.52 in) wide, not the 33 in in its name.
Sidewall = (diameter − rim) ÷ 2 = (32.52 − 15) ÷ 2 = 8.76 in.
Inch sizes: see inch tire sizes explained. Revolutions per mile = 63,360 ÷ circumference. Full sources are listed at the end of this page.
Questions about 33x12.50R15
- How tall is a 33x12.50R15 tire?
- 32.52 inches (826.0 mm) nominal. A new tire may measure from 31.99 to 33.75 in under the official tolerance; the maker's specification gives the figure for a specific tire.
- How wide is a 33x12.50R15 tire?
- 12.52 inches (318.0 mm) section width. Overall width can be slightly larger; for passenger tires, US rule FMVSS 139 allows 7% over the specified width (or 10 mm, if larger, for some pressure classes).
- How many revolutions per mile does 33x12.50R15 make?
- About 620 nominal, from a circumference of 102.16 in. Tire makers publish measured revolutions per mile for each tire.
- Will 33x12.50R15 fit my vehicle?
- This page can't tell you. Check the tire size on your door-jamb placard, then confirm wheel width, offset and clearance with the tire or vehicle maker.
Related
Printed from https://tiresizecalc.net/size/33x12-50r15/. Figures as published on 2026-11-01. The full working and the official sources are on that page.
Sources
This size is listed by the manufacturer: BFGoodrich All-Terrain T/A KO3, checked on the manufacturer's site on 2026-11-01. The size page shows nominal figures, not that product's measurements.
- UN Regulation No. 30 - Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers (Revision 3). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.29/Rev.3. 2007-03-29. Para 2.15 and 6.1.2.1: aspect ratio and outer diameter, D = d + 2H. Retrieved 2026-11-01.
- UN Regulation No. 54 - Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers (Revision 2). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.53/Rev.2. 2004-04-16. Para 6.1.2.1: the same formula for light truck tires. Retrieved 2026-11-01.
- UN Regulation No. 30 - Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers (Revision 3). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.29/Rev.3. 2007-03-29. Para 6.1.5: allowed outer diameter, Dmin = d + 2H x 0.97, Dmax = d + 2H x 1.04. Retrieved 2026-11-01.
- UN Regulation No. 54 - Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers (Revision 2). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.53/Rev.2. 2004-04-16. Annex 5 Part II Table B: design outer diameter and section width of 33x12.50R15LT. Retrieved 2026-11-01.
- UN Regulation No. 54 - Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers (Revision 2). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.53/Rev.2. 2004-04-16. Para 6.1.5.1, 6.1.5.3.1 and Table B note 2: allowed outer diameter for table sizes. Retrieved 2026-11-01.
- Computed by tiresizecalc.net from the cited formula. Sri Murugan Systems. Not in UN R54 Annex 5 Table B: diameter and width of 33x12.50R17 are the numbers in the size. Retrieved 2026-11-01.
- Computed by tiresizecalc.net from the cited formula. Sri Murugan Systems. Circumference = pi x diameter; revolutions per mile = 63,360 / circumference; 1 in = 25.4 mm exactly. Retrieved 2026-11-01.
- 49 CFR 571.139 - Standard No. 139; New pneumatic radial tires for light vehicles. National Highway Traffic Safety Administration (NHTSA), Code of Federal Regulations (eCFR). 49 CFR 571.139. eCFR up to date as of 2026-10-15. S6.1.2: passenger tire width up to 7 percent (or 10 mm) over the specified width. Retrieved 2026-11-01.
- 49 CFR 571.110 - Standard No. 110; Tire selection and rims for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less. National Highway Traffic Safety Administration (NHTSA), Code of Federal Regulations, annual edition (GovInfo). 2006-10-01. S4.3: the door placard shows the original tire size. Retrieved 2026-11-01.
Last reviewed 2026-11-01. The full source list, with dates and file checksums, is in How the numbers are calculated. To report an error, email contactus@tiresizecalc.net.