31-inch tire sizes
These 7 sizes measure between 30.5 and 31.5 inches tall (nominal), so they're all called 31-inch tires.
| Size | Diameter | Width | Rim |
|---|---|---|---|
| 245/70R17 | 30.50 in | 9.65 in | 17 in |
| 265/60R18 | 30.52 in | 10.43 in | 18 in |
| 265/65R17 | 30.56 in | 10.43 in | 17 in |
| 265/70R16 | 30.61 in | 10.43 in | 16 in |
| 265/75R15 | 30.65 in | 10.43 in | 15 in |
| 255/70R17 | 31.06 in | 10.04 in | 17 in |
| 245/75R17 | 31.47 in | 9.65 in | 17 in |
A "31-inch tire" is a rounded name. A real new tire can differ from nominal within the official tolerance shown on each size page; check the maker's published diameter. See inch tire sizes.
Printed from https://tiresizecalc.net/inch/31-inch-tires/. Figures as published on 2026-11-01. The sources are listed below.
Sources
- 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.
- 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.
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.