Tire fitment
The 2025-2026 Ram 1500 base tire size is 275/65R18 — 275 mm wide with a 65% aspect ratio on 18″ rims. 4 OEM sizes are available across trims.
2025-2026 Ram 1500
275/65R1832.1″ overall diameter · 178.8 mm sidewall · ~629 rev/mi
| Trim | Tire size | Rim | Diameter | vs Base |
|---|---|---|---|---|
| Big Horn/Lone Star ★ | 275/65R18 | 8×18″ | 32.1″ (814.7 mm) | — |
| Laramie | 275/55R20 | 9×20″ | 31.9″ (810.5 mm) | -0.52% |
| Limited | 285/45R22 | 9×22″ | 32.1″ (815.3 mm) | +0.07% |
| RHO | 325/65R18 | 9×18″ | 34.6″ (879.7 mm) | +7.98% |
35-inch all-terrain, replaces TRX.
The 2025-2026 Ram 1500 ships with 275/65R18 tires on the base trim — that's an overall diameter of 32.1″. The 275 mm width and 65% sidewall ratio give you 178.8 mm of sidewall cushion between the rim and the road.
Match the load index and speed rating from your door-jamb placard — not just the size. If you're switching sizes, keep the overall diameter within ~3% to avoid speedometer error and potential ABS/traction-control issues.
Factory fitment for the 2025-2026 Ram 1500; verify against your door-jamb placard or owner's manual.
The base 2025-2026 Ram 1500 uses 275/65R18 tires — 275 mm wide, 65% aspect ratio, on 18-inch rims. The overall diameter is 32.1″ (814.7 mm). Higher trims use different sizes — see the table above. Confirm against your door-jamb placard.
Yes, within limits. Keep the overall diameter within about 3% of 32.1″ to avoid speedometer error and clearance issues. A wider tire may improve grip, but match the load and speed ratings your 1500 requires.
275/65R18 tires have an overall diameter of 32.1″ (814.7 mm), with a 178.8 mm sidewall height. That's about 629 revolutions per mile.
The 2025-2026 Ram 1500 tire sizes shown are OEM factory fitments. Confirm your exact tire size, load rating, and speed rating against the door-jamb placard or owner's manual before buying tires.