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How to Measure Your Truck Bed Length for a Tonneau Cover

Where to put the tape, why your number won't match the brochure, and a bed length chart for the F-150, Silverado, Sierra, Ram, Tacoma, Tundra and more.

Buying guideBy The RideIntel Team5 min read

Bed length is the single most common reason a tonneau cover goes back. Not because people can't use a tape measure, but because truck makers, cover makers and owners all describe the same bed with different numbers. Ford calls its short bed 5.5 ft, most cover makers sell it as 5'7", and a tape on the bed floor gives a third answer. This guide shows where to measure, how to translate the number, and what each popular truck actually has.

Who This Guide Is For

Anyone ordering a tonneau cover, bed liner, bed mat or bed rack who wants to be sure of the bed size before buying. It takes five minutes and a tape measure.

What You'll Need

  • A tape measure of at least 10 ft
  • Your truck on level ground with the tailgate closed
  • Your model year, from the registration or the driver's door jamb sticker

Step 1: Measure at the Top of the Bed Rails

Tonneau covers sit on the bed rails, so measure where the cover will sit:

  1. Hook the tape on the inside edge of the front bulkhead (the bed wall behind the cab), at the top of the rail.
  2. Run it straight back to the inside of the closed tailgate, at the same height.
  3. Read the length in inches.

Step 2: Don't Use the Bed Floor

Measuring along the floor gives a different number on many trucks, because bed walls and tailgates aren't perfectly vertical. Floor length is what truck makers sometimes quote for cargo; rail length is what fits a cover. When a cover maker's chart and your floor measurement disagree, the rail measurement is the one that matters.

Step 3: Account for Liners and Seals

A drop-in liner that wraps over the bulkhead or the tailgate adds thickness at the ends. Measure from the painted metal where you can, or subtract the liner's thickness. Spray-in liners add almost nothing.

Step 4: Round to the Nearest Listed Size

Your measurement will rarely match a listing exactly. Variance of about an inch between trucks is normal and doesn't affect fit, because covers are made for the bed's nominal size. Pick the listed size closest to your measurement for your model year, then confirm with the chart below.

Bed Length Chart: What Each Truck Actually Has

TruckModel yearsTruck maker's bed lengthsHow covers are often listed
Ford F-1502015+5.5 ft, 6.5 ft, 8 ft5'7", 6'7", 8'2"
Chevy Silverado 15002019+5'10", 6'7", 8'2"Short box often 5'8"
GMC Sierra 15002019+5'10", 6'7", 8'2"Short box often 5'8"
Ram 15002019+5'7", 6'4"5'7", 6'4"
Toyota Tacoma2016+5 ft, 6 ftAbout 60 in and 74 in
Toyota Tundra2022+5.5 ft, 6.5 ft, 8.1 ft5.5 ft (sometimes 5'6"), 6.5 ft, 8.1 ft
Ford Ranger2019+5 ft, 6 ft (2019-2023 SuperCab)5 ft often 5'1"
Chevy Colorado2015+5'2", 6'2" (2015-2022 only)5'2", 6'2"

Each of these trucks has a vehicle-specific cover guide with the fitment traps for that model: F-150, Silverado 1500, Sierra 1500, Ram 1500, Tacoma, Tundra, Ranger and Colorado.

Length Is Only Half of Fitment

Two trucks with the same bed length can still need different covers. After length, check:

Generation

Model names carry across redesigns, beds don't. The F-150 changed for 2021, the Tacoma and Ranger for 2024, the Colorado for 2023 and the Tundra for 2022. A 2020 F-150 cover will not fit a 2022 F-150 even though both have a "5.5 ft" bed.

Factory options

  • Split or multi-function tailgates (Ram multifunction, GM Multi-Flex and MultiPro, Ford Pro-Access)
  • Bed storage (RamBox)
  • Rail systems (Toyota deck rails, Ram Utility Track System)
  • Bed material (GMC CarbonPro)

Cab style

Cab style limits which beds a truck can have. On a 2019+ Ram 1500, for example, Quad Cabs only come with the 6'4" bed, while Crew Cabs offer 5'7" or 6'4".

Common Mistakes

  • Measuring with the tailgate down. You'll get the floor length plus the tailgate. Close it.
  • Trusting the window sticker's "box length". It may be a floor or nominal number. Measure the rails.
  • Buying by model name instead of model year. The generation matters as much as the length.
  • Ignoring a liner. Over-the-rail liners change both length and clamp clearance.

Final Thoughts

Measure at the rails, round to the nearest listed size, then confirm the generation and factory options. Once you know all three, see our best truck bed covers or the guide for your truck, and the tonneau cover types guide if you haven't settled on a style.

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