2025 Ram 1500: the quick answer
The 2025 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.
Tire fitment
2025 Ram 1500 tire size
The 2025 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 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.
Before you buy tires
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 Ram 1500; verify against your door-jamb placard or owner's manual.
FAQ
What tire size does the 2025 Ram 1500 use?
The base 2025 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.
Can I use a different tire size on my 2025 1500?
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.
What is the overall diameter of 275/65R18 tires?
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 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.