How to Measure Your Truck Bed for a Tonneau Cover

Ordering a tonneau cover, bed mat, or truck cap starts with one number: your bed length. Marketing names like “short box” and “standard box” vary between brands, so measure it yourself — it takes two minutes.

The right way to measure

1. Open the tailgate.
2. Run a tape measure inside the bed, from the inside of the bulkhead (the wall behind the cab) to the inside edge of the closed-tailgate position.
3. Round to the nearest inch and convert: 66″ ≈ 5'5″, 78″ ≈ 6'5″, 96″ = 8'.

Don't measure the outside of the bed, include the tailgate, or trust the dealer sticker — the inside measurement is what covers and mats are cut to.

Common bed lengths by truck

• Ford F150: 5'5″ or 6'5″
• RAM 1500: 5'7″ or 6'4″
• Chevy Silverado / GMC Sierra 1500: 5'8″ or 6'6″
• Toyota Tundra: 5'5″ or 6'5″
• Toyota Tacoma: 5' or 6'
• Heavy duty (F250/F350, RAM 2500/3500, Silverado/Sierra HD): ~6'4″–6'9″ standard, 8'+ long box

Your measurement should land within an inch of one of these — if it doesn't, double-check that you measured inside the bed.

Why year range matters too

Bed rail design changes between truck generations, so a cover for a 2015–2020 F150 won't sit right on a 2021+ body. Every TruckTon tonneau cover and bed mat page has a year selector plus bed-length options, so the combination you pick is the exact part that ships.

Measured? Here's your next step

Take your bed length to the product page for your truck — for example the Ford F150 Hard Flip-Back Tonneau Cover — select your year and bed size, and the fit is guaranteed to match what you selected. Still unsure? Send us your truck's year, model and measurement via the contact page and we'll confirm the right size, 7 days a week.