Short answerClose the tailgate. Measure length along the bed from the front wall to the inside of the tailgate. Measure width wall to wall, then again between the wheel wells. Use the narrower width for anything that sits flat in the bed, and round down, not up.
You need your bed size before you buy a tonneau cover, a bed liner or a bed system. It takes two minutes and a tape measure.
What you need
- A tape measure, at least 10 feet
- An empty bed (pull a drop-in liner if you have one)
- The tailgate closed
Step 1: Measure the length
Lay the tape flat along the bed, from the front wall (the cab end) to the inside of the closed tailgate. Measure along the bed itself, not across the top of the rails. This is your bed length.
Step 2: Measure the width, wall to wall
Measure across the bed from one side wall to the other, at the front of the bed. This is the widest width, used for things that sit up by the bed rails.
Step 3: Measure between the wheel wells
The wheel wells stick into the bed on both sides. Measure the gap between them. On most trucks this is the narrowest point of the bed, and it’s the number that matters for anything that sits flat on the bottom of the bed, like a bed system or a sheet of plywood.
Which number do I use?
| Buying | Use |
|---|---|
| A tonneau cover | Your bed length, by make, model and years |
| A bed system that sits in the bed | Length, plus the width between the wheel wells |
| Something that sits on the rails | Width wall to wall |
Tips for a good measurement
- Round down. A half inch too big doesn’t fit. A half inch small does.
- Measure twice. Once on each side of the bed.
- Keep the tape flat. A tape that bows up adds length.
Measured your bed? Here’s what to do with the numbers
Look your truck up in our truck bed size chart, or pick your truck to see the DIALED System sized to it. If your truck isn’t listed, enter your width and length in the sizing calculator. It lays out every piece on a 2 in grid and rounds down to the nearest 2 in, so it always fits. Every system has a 90-day fit guarantee.
