245/75R17 Tire Size in Inches | Diameter, Width & Fit

A 245/75R17 tire measures about 31.5 inches in diameter, 9.65 inches in width, and fits a 17-inch rim.

For the full breakdown, see our best 245/75R17 Tires guide.

If you’re swapping tires, lifting a truck, or checking clearance, the inches conversion matters more than the metric label. The 245/75R17 size breaks down to a 31.47-inch overall diameter, a 9.65-inch section width, a 7.23-inch sidewall, and a 98.86-inch circumference, per TireSize.com’s reference data. Those numbers tell you exactly what will fit under your fenders and how the tire will change your speedometer reading.

245/75R17 Explained: What Each Number Means

The metric code on your tire’s sidewall isn’t random. Each segment describes a specific physical dimension of the tire, and each one converts to inches differently.

• 245 – the nominal section width in millimeters, measured from the widest point of the sidewalls. Divide by 25.4 to get 9.65 inches.
• 75 – the aspect ratio, meaning the sidewall height is 75% of the width. That’s 183.75 mm, or 7.23 inches.
• R – radial construction, the standard for modern passenger and light-truck tires.
• 17 – the rim diameter in inches the tire is designed to mount on.

The formula for overall diameter is simple: 2 × sidewall height + rim diameter. With a 7.23-inch sidewall on a 17-inch wheel, that works out to roughly 31.5 inches.

245/75R17 Dimensions: Inches, Millimeters, and What Varies

Here are the key measurements for the 245/75R17 tire size, drawn from trusted tire-size references. Treat these as nominal values — actual dimensions shift slightly by brand, tread pattern, and inflation pressure.

That 31.5-inch diameter classifies this as a light-truck or SUV tire size, commonly found on trucks like the Ford Ranger and SUVs where ground clearance matters. The Tire Size reference for 245/75R17 shows a typical approved rim width of 6.5 to 8.0 inches for passenger tires, so check your wheel’s stamped width before mounting.

Fitment and Clearance: What Works Before You Buy

A 245/75R17 tire only fits vehicles with 17-inch wheels and enough clearance for a tire that’s roughly 31.5 inches tall. That means checking more than just the rim size — suspension geometry, fender lining, and steering lock all matter.

Compare sizes before you commit. The Ranger Station’s tire-size chart confirms that 245/75R17 runs about 3.1% taller than the narrower 245/70R17. When in doubt, measure your current setup and mock up the new diameter with a tape measure.

Common Mistakes to Avoid with 245/75R17

Tire sizing trips up even experienced owners in a few predictable places. Here’s what to watch for:

• Confusing section width with diameter. The 245 refers to width, not height.
• Assuming 17-inch rims fit any 245/75R17. Rim width range matters; a 6-inch-wide wheel will pinch the tire, and an 8.5-inch wheel will stretch it.
• Treating 31.5 inches as an exact measurement. Different brands vary slightly, so verify with the manufacturer’s spec sheet for the exact model you want.

Once you’ve confirmed the dimensions work for your vehicle, the next step is picking a tire that matches your driving — whether that’s highway mileage, off-road grip, or all-season balance. Our roundup of the best 245/75R17 tires breaks down the top options by tread life, traction, and value to help you narrow the field.