325/75R16 measures 35.2″ overall diameter and 12.8″ section width. Sidewall height is 9.6″, circumference is 110.6″, and the tire turns 573 times per mile. Those figures are geometry off the stamped size, not a brand or load range.
325/75R16 dimensions
| Measurement | Inches | Metric |
|---|---|---|
| Overall diameter | 35.2″ | 894 mm |
| Section width | 12.8″ | 325 mm |
| Sidewall height | 9.6″ | 244 mm |
| Circumference | 110.6″ | 2808 mm |
| Revolutions per mile | 573 | 356 / km |
The stamped width is 325 mm (12.8″). The aspect ratio is 75, so the sidewall is 75% of that width, which is 9.6″. The rim is 16 inches. Overall diameter is the rim plus two sidewalls: 16 + 2 × 9.6″ = 35.2″.
Sizes near 325/75R16
A swap that stays inside about 3% diameter usually keeps the speedometer honest and clears the same well. 315/75R16 is a close neighbour at -1.7% diameter. The percent column opens both stamps in the comparison calculator.
| Size | Diameter | Width | vs 325/75R16 |
|---|---|---|---|
| 315/75R16 | 34.6″ | 12.4″ | -1.7% |
| 295/65R20 | 35.1″ | 11.6″ | -0.3% |
| 35x12.50R17 | 35.0″ | 12.5″ | -0.5% |
| 35x12.50R18 | 35.0″ | 12.5″ | -0.5% |
| 35x12.50R20 | 35.0″ | 12.5″ | -0.5% |
| 285/75R18 | 34.8″ | 11.2″ | -1.0% |
How to read the stamped size
325/75R16 is a metric size: width in millimetres, aspect ratio as a percent of that width, then the rim diameter in inches after the R. The how to read tire size page walks the whole sidewall, including load index and speed rating, which this page does not use.
Diameter and width tell you whether a size is in the same family as what you have. They do not tell you whether 325/75R16 clears your fenders, matches your wheel width, or is load-rated for the vehicle. Check the door-jamb sticker and the wheel well before you buy.
Speedometer and revs
At 573 revolutions per mile, a trip computer calibrated for 325/75R16 is reading true only while this diameter is on the truck. A taller replacement under-reads speed and distance by the same percent the diameter grew. A shorter one over-reads. The comparison calculator puts a second size next to 325/75R16 and shows the error at 60 mph.