If you're shopping for a tonneau cover, bed mat or truck cap, the first question is always the same: which of the RAM 1500 bed sizes do you actually have? RAM has sold three different box lengths — 5'7", 6'4" and 8' — and ordering an accessory for the wrong one is the most common (and most avoidable) fitment mistake we see. The differences matter more than a few inches of steel: bed length is tied to cab configuration, model generation and even which accessories exist for your truck at all.
This guide breaks down all three RAM 1500 bed sizes, explains how the 2019 body-style change complicates things, and shows you how to confirm what's in your driveway before you order anything.
The Three RAM 1500 Bed Sizes at a Glance
RAM measures its beds the same way every truck maker does: interior floor length, cab to tailgate, with the gate closed. The marketing names round to friendly numbers, so the actual measurements are a little different:
- 5'7" bed — roughly 67 inches (about 170 cm) of floor length. The short box.
- 6'4" bed — roughly 76 inches (about 193 cm). RAM's standard box.
- 8' bed — roughly 96 inches (about 244 cm). The long work box, offered on older and Classic-series trucks.
That's why a tape measure reading of 67 inches means you have a "5'7"" bed even though 5'7" is technically 67 inches on the nose only if you're lucky with your measuring angle. If your number lands within an inch or two of one of those figures, that's your bed.
The 5'7" Bed: The Crew Cab Favourite
The 5'7" box is what most Canadian RAM 1500s on the road today carry, because it's the default partner of the Crew Cab — the four-full-door configuration most families and daily drivers choose. You give up bed length to get that back seat.
For most owners it's a fair trade. A 5'7" bed still swallows groceries, hockey bags, camping gear and most home-renovation runs, and with the tailgate down you can carry 8-foot lumber (strapped properly). It's also the cheapest bed to accessorize and the easiest to cover: a short box means shorter, stiffer tonneau panels and less material to seal against weather.
Because it's the volume seller, the 5'7" bed has the widest accessory support. Every RAM cover we stock — from the soft tri-fold ($349.99 CAD) to the low-profile hard tri-fold ($599.99 CAD) and the hard flip-back cover ($699.99 CAD) — comes in a 5'7" version.
The 6'4" Bed: The Do-It-All Standard
The 6'4" box is RAM's standard bed, and it's the one to want if your truck earns its keep. The extra nine inches over the short box is the difference between a quad's ramps sitting flat and hanging off the tailgate, and between sheet goods riding mostly supported versus mostly hoping.
On new-body-style trucks (2019 and newer), the 6'4" bed comes on the Quad Cab and is optional on the Crew Cab. On the older body style it was the workhorse default. It's heavily supported by accessories too — the same soft, low-profile and flip-back covers above all come in 6'4" versions, as does our RAM 1500 bed mat ($139.99 CAD).
One honest note for winter: more bed means more snow to clear off a soft cover after a storm. If your truck lives outside year-round, a hard cover's rigid panels handle Canadian snow loads with less fuss — we cover this in detail in our hard vs soft tonneau comparison.
The 8' Bed: The Work-Truck Holdout
The 8-foot box is the long-bed configuration, historically paired with the Regular Cab on work-spec trucks, and it carried on longest in the RAM 1500 Classic line that stayed in production alongside the new body style. If you own one, you already know its superpower: full sheets of plywood and drywall lie flat with the tailgate up.
The trade-off is aftermarket support. The 8' bed is a small slice of RAM 1500 sales, so accessory options are thinner across the whole industry — and we'll be upfront: our current RAM 1500 tonneau covers are made for the 5'7" and 6'4" beds. If you have an 8-footer, get in touch before ordering anything and we'll tell you honestly what fits.
Classic vs New Body Style: Why Model Year Matters
Here's the wrinkle that catches RAM owners more than anyone else: from 2019 until recently, RAM sold two different trucks under the same name. The new body style (often called the DT) launched for 2019, while the previous-generation truck continued as the RAM 1500 Classic — a popular choice in Canada because of its lower price.
The two generations have different bed rail shapes and dimensions, so a cover for a 2020 new-body truck will not fit a 2020 Classic, even in the same nominal length. That's why our product pages list variants like "5'7" / 2019–2026 (New Style)" and "5'7" / 2009–2018 (Classic)" — the year range and body style matter as much as the length. When ordering, match all three: bed length, year range, and body style.
A related gotcha: if your truck has the RamBox cargo-management system (the lockable bins built into the bed rails), the top of your bed is a different shape and standard clamp-on covers won't mount. Check for RamBox before ordering any tonneau cover, and contact us if you're unsure.
How Cab Choice Locks In Your Bed Length
You generally don't pick a RAM bed length in isolation — the cab decides it for you:
- Crew Cab (four full doors): 5'7" bed standard, 6'4" available.
- Quad Cab (four doors, smaller rears): 6'4" bed.
- Regular Cab (two doors, Classic/work trucks): 6'4" or 8' bed.
So if you know your cab, you've usually narrowed the bed to one or two possibilities. Crew Cab owners are the ones who genuinely need to measure, since both short and standard boxes were offered.
How to Confirm Your Bed Size in Two Minutes
Don't trust the sales listing, the previous owner's memory, or the badge package — measure. Hook a tape measure on the inside of the bulkhead (the wall behind the cab), run it along the bed floor to the inside of the closed tailgate, and read the number: about 67 inches is a 5'7", about 76 inches is a 6'4", about 96 inches is an 8-footer.
We've got a full walkthrough with photos in our guide on how to measure your truck bed for a tonneau cover — worth two minutes before you spend a few hundred dollars on a cover.
Matching Accessories to Your RAM 1500 Bed
Once you know your bed length, year range and body style, the rest is easy. For covers, start with our RAM 1500 tonneau cover buyer's guide, which compares the soft, low-profile and flip-back options in detail. A bed mat pairs with any cover and protects the floor from road salt and cargo scuffs — and yes, covers and mats work together, as we explain in our bed liner and bed mat compatibility guide. If you need full-height weather protection instead, the RAM 1500 aluminum truck cap ($2,999.99 CAD) is built for both short- and standard-bed trucks.
Everything ships free anywhere in Canada, carries a 2-year warranty, and uninstalled items can be returned within 30 days. If you're near Burlington, Ontario, we'll install your cover free with local pickup.
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