245/60R18 tire size — the 18-inch 60-series family, measured
A mid-size crossover and light-SUV fitment, second rung of a five-size family whose spacing changes at the top.
Metric notation · Crossover and SUV
- Overall diameter
- 29.57 in
- 751 mm
- Section width
- 9.65 in
- 245 mm
- Sidewall height
- 5.79 in
- 147 mm
- Aspect ratio
- 60%
- sidewall as a share of width
- Wheel diameter
- 18 in
- the hole in the middle
- Circumference
- 92.9 in
- 2360 mm
- Revolutions per mile
- 681.9
- geometric, not measured
- Revolutions per km
- 423.7
- geometric, not measured
- Typical load index
- 98–116
- 1653–2756 lb per tire
Crossovers are heavier than the cars they share size families with, so the same nominal size is produced at a higher index for SUV fitment than for passenger fitment. Two tires wearing the same size code can carry materially different loads.
The load-index range shown is the band this CLASS of size is typically produced in — not a list of what is in stock for this exact size today. Load index and speed symbol are printed on the sidewall of the specific tire you are holding, and the required minimum is on the placard of the specific vehicle you are fitting. Read both.
Nearest real sizes in imperial notation, same wheel
- 33x12.50R1833.00 in tall+3.43 in
- 35x12.50R1835.00 in tall+5.43 in
- 37x12.50R1837.00 in tall+7.43 in
Compare any two sizes, including ones this site has no page for, in the comparison tool.
Platforms recorded with this size
Mid-size crossovers, light SUVs and a number of all-wheel-drive estates. The 60-series aspect ratio on an 18-inch wheel is the current default for a vehicle that needs about 29 to 30 in of rolling diameter and a comfortable ride.
Five widths, and a step that changes
| Size | Section | Diameter | Step from previous |
|---|---|---|---|
| 235/60R18 | 9.25 in | 29.10 in | — |
| 245/60R18 | 9.65 in | 29.57 in | +0.47 in |
| 255/60R18 | 10.04 in | 30.05 in | +0.47 in |
| 265/60R18 | 10.43 in | 30.52 in | +0.47 in |
| 285/60R18 | 11.22 in | 31.46 in | +0.94 in |
The first four rungs are 10 mm apart and step by 0.47 in each. The last is 20 mm apart, because 275/60R18 is not a size the market stocks in volume, and it steps by twice as much. Reading a family table without checking the width column is how a jump like that gets missed.
From the narrowest to the widest is 2.36 in of diameter and 8.12%.
Its counterparts on other wheels
245/65R17 measures 29.54 in — 0.12% from this size, with the same 9.65 in section and 6.27 in of sidewall instead of 5.79 in. 245/50R20 measures 29.65 in with 4.82 in. The same tread width appears on three wheel diameters at essentially one rolling diameter, which is how a manufacturer offers three visually different packages on one drivetrain calibration.
Where the class boundary falls
Every size in the table above is a crossover fitment except 285/60R18, which is classed as light truck. Nothing in the geometry marks the change — the difference is in casing construction and rated load, neither of which is encoded in the size. The load range and ply rating reference sets out the letters that do carry it.
Read the load index on the sidewall against the door-jamb placard figure; the load index table converts both.
The figure the gearing sees
681.9 revolutions per mile is what the axle ratio multiplies against to produce engine speed at a given road speed. Moving one rung up the table to 255/60R18 drops the count and lengthens the gearing by 1.60%; moving one rung down to 235/60R18 shortens it by the same proportion. The gear ratio calculator works the arithmetic through for any axle.
Related
- 33x12.50R1833.00 in tall
- 35x12.50R1835.00 in tall
- 37x12.50R1837.00 in tall
Class: Crossover and SUV. Every figure above is computed from the size code, not stored — see how these numbers are calculated.