Will Bigger Tires Fit My Truck? How to Check Before You Buy

Look at the sidewall. A size like 275/65R18 means 275 mm wide, a sidewall that is 65% of the width, on an 18-inch wheel. Off-road tires are often listed in inches instead, such as 35x12.50R20: 35 inches tall, 12.5 inches wide, 20-inch wheel.

To estimate the overall diameter of a metric tire: (width × aspect ratio ÷ 100 × 2 ÷ 25.4) + wheel diameter. For 275/65R18 that is about 32.1 inches.

• Front upper control arm and inner fender liner at full steering lock.
• Front bumper, air dam and mud flaps when turning.
• Body mount and cab corner on full suspension compression.
• Rear wheel well when the suspension is loaded or flexed.

On a stock truck, going roughly one inch taller in overall diameter usually fits without changes. A leveling kit typically adds room for another inch or so. Beyond that, you’re usually looking at a lift kit, trimming, or wheels with a different offset.

Numbers vary a lot between models, generations and trims, so treat any general rule as a starting point and confirm with the tire and wheel maker’s fitment data for your exact truck.

Wheel width and offset move the tire in or out. A lower or negative offset pushes the tire outward, away from the suspension but closer to the fender edge. See our guide on offset and backspacing for how to compare wheels.

• Speedometer and odometer read low. Recalibration is usually recommended.
• Heavier tires can reduce acceleration, braking performance and fuel economy.
• Larger tires effectively change your gearing, which you may feel when towing.
• Load rating matters: choose a tire whose load index meets or exceeds your truck’s requirements, shown on the door jamb placard.