Truck Bed Length: How to Measure and Match a Tonneau Cover

Every tonneau cover listing is for a specific bed on a specific run of model years, and it names that bed however its maker likes. A tape measure settles which bed you have in a few minutes, and it settles it better than the name you've always called the bed.

Skip the tape and the cover can arrive a foot short. That's what happened to a Nissan Frontier owner who ordered a 5 ft Roll-N-Lock in the excitement of a new truck and found out at install time. The Frontier isn't a truck we cover, and the same slip costs the same on any pickup.

Bed mats and liners work the same way with one change: they're measured on the floor, not along the rail.

How to measure your bed

This is RealTruck's method, with one step of ours added at the start. RealTruck sells TruXedo, BAK, UnderCover, Retrax and BedRug, the brands behind most of the listings below. You need a tape long enough to span the bed; a helper to hold the end makes it easier.

1. Close the tailgate (our step). RealTruck doesn't say open or closed, but its length step ends at the inside edge of the top of the tailgate, and that edge is only there with the gate up and latched.
2. Hook the tape at the bulkhead. For a tonneau cover, set the end of the tape flush against the front wall of the bed at the top of the bed rail, not down on the floor.
3. Run it straight back along the rail. Keep it straight, stop at the inside edge of the tailgate and write down the figure in inches.
4. For a mat or liner, measure the floor. RealTruck's instruction for bed mats and liners is to measure along the bed floor, from the bulkhead to the inside edge of the tailgate, instead of along the rails.
5. Write down everything else too. RealTruck says to note rail caps, utility tracks, cargo systems and toolboxes, and whether a drop-in liner is fitted. We'd add the model year, the cab and the tailgate. The next sections explain why each one matters.

RealTruck lists measuring to the outside of the tailgate instead of the inside edge as one of the most frequent mistakes, and says it can add several inches. Don't expect your figure to match a listing title to the inch, either. RealTruck says truck makers round their advertised bed sizes and that some are off by multiple inches, and cover listings name beds their own way on top of that. Your tape is for finding out which bed you have, not for reading off a part number.

One bed, several names

Here is how cover and bed listings name each bed, as their titles give it, plus Peragon, which sells direct and names beds on its own site. Brand names in parentheses are whose listings use that name; the inch figure is shown where the listing gives one.

Do the subtraction and the confusion mostly goes away. The inch figures for one bed differ by an inch or two, about 3 in on the Colorado and Canyon, while a truck's two shortest beds are roughly 8 to 13 in apart: 67.1 in against 78.9 in on the F-150, 69.9 in against 79.4 in on the Silverado, 67.4 in against 76.3 in on the Ram. A tape reading lands near one bed and nowhere near the next, so it tells you which bed to buy for even when it matches no title.

So match by the inch figure first and the name second. The 5.5 ft and 6.5 ft names F-150 owners use show up only on Tyger's F-150 listings in the table above. GM and RealTruck's own part pages call the Silverado short bed 5 ft 8 in, yet most of RealTruck's Amazon titles say 5 ft 10 in for the same 69.9 in bed. On the Maverick, the Sentry CT's listing says 4 ft 6 in where RealTruck's page for the part says 4 ft 4 in. They're all one bed.

Mats, liners and bed storage follow their own conventions. BedRug's titles mostly give the inch figure alone (67.4, 76.3, 78.9, 97.6), which makes them the easiest to match against a tape. DECKED's drawer listings give a feet-and-inches name only, and its Silverado listing is a warning: the title says 5 ft 9 in, while its own bullet says the system is built for a 5 ft 6 in bed.

Generation and model year come before length

A bed length means nothing without the generation. Two trucks can share a bed name and still need different covers, so start every search with the model year and only then the bed.

• F-150, Gen13 (2015-2020) and Gen14 (2021 on): both generations use the same bed names, and the picks handle them differently. A single Sentry CT or Lo Pro listing per bed reads 2015-2027, and one T3 listing serves the 6.5 ft bed from 2015 to 2026. The Ultra Flex is sold as separate Gen13 and Gen14 parts, and the T3's 5.5 ft bed changes part at 2021. Part numbers are a listing decision, not proof of what fits, so order the listing that names your model year.
• Tacoma, 3rd gen (2016-2023) and 4th gen (2024 on): each of our picks is sold as a different part for each generation, and the bed names change too: RealTruck's 3rd gen listings say 5 ft 1 in, while most 4th gen listings say 5 ft.
• Ranger, 2024-2025 and 2026: treat them as different trucks. An owner who moved from a 2024 Ranger to a 2026 found the BAKFlip G2 off the old truck wouldn't fit the new one, since the bed rails had changed slightly, and RealTruck sells the G2 as a separate part for the 2026-2027 Ranger. The Lo Pro and T3 Ranger listings we confirmed end at 2025.
• Silverado and Sierra 1500, 2019: a 2019 can be either generation, because the outgoing truck stayed on sale that year badged Silverado 1500 LD or Sierra 1500 Limited, and its covers are different parts. Check which one you have first. The T3's listings exclude the 2019 LD and Limited by name, yet list the 2022 Silverado 1500 LTD and Sierra 1500 Limited as fits, so the badge alone doesn't settle it.
• Ram 1500, DT and Classic: the DT arrived for 2019, and the older truck carried on as the Ram 1500 Classic. Tyger says its DT T3 doesn't fit 2019-2024 Classic models, and Peragon's Ram page gives Classic and New Style beds their own entries. Most of the Sentry CT's and Ultra Flex's DT listings don't name the body style at all, so confirm the listing is for the DT before you buy.
• Maverick: some listings, BAK's G2 among them, start at 2021 even though the truck launched for 2022. That's the listing's wording, not a different bed.

A cover can survive a generation change. One owner's Ford tri-fold, original to a 2017 F-150, went onto a 2021 and still seals. That's a good outcome, not a promise, and we wouldn't buy a used cover for a different generation on the strength of it.

Cab, rails and tailgate: the fine print that decides the listing

Once you know the bed, the restrictions pick between a cover's listings for it. Most of them live in the listing's fitment bullets rather than its title, so read the bullets.

• Cab. On most trucks the bed, not the cab, decides the cover, and most listings never mention the cab. Where one does, it counts. On the 3rd gen Tacoma, the RetraxPRO XR's 5 ft 1 in listing is for the Double Cab only, while the 6 ft 2 in one lists Regular, Access and Double Cab trucks.
• Toyota rails and storage boxes. Listings call Toyota's factory rails the deck rail system, the OE track system, the utility rail system or the Utility Track System. All four of our picks need them on a 4th gen Tacoma, by the listing's own wording or RealTruck's. On the Tundra short bed, the Sentry CT's listing is for trucks without the rails and the Lo Pro's for trucks with them. 3rd gen Tacoma and Tundra listings often exclude the Trail Special Edition storage boxes.
• Ford BoxLink and Maverick tracks. A cover can cost you factory tie-down points. The RetraxPRO XR's canister sits over a Gen14 short bed's front anchors and the BoxLink holes nearest the cab. The T3's Maverick listing rules out trucks with a Utility Track System, Tyger's term, and doesn't define it.
• RamBox, the multifunction tailgate and the TRX. Ram listings split by RamBox and by the multifunction (split) tailgate, often into three versions for one bed, and RealTruck says to remove the Ram TRX bed bar for the Ultra Flex's 5 ft 7 in part.
• GM tailgates, CarbonPro and storage boxes. The Sentry CT, Ultra Flex and Lo Pro listings say they work with the MultiPro/Flex tailgate. The CarbonPro composite bed gets its own listing, factory side storage boxes rule some covers out, and the T3 is out with a power tailgate.
• Liners. An over-the-rail drop-in liner can need small holes cut for a cover's clamps; Tyger says so for the T3. BedRug's mat listings are for beds with no liner or a spray-in, and its full bedliner listings call for its adhesion kit over a spray-in.

Titles and bullets don't always agree, either. LEER's F-150 short-bed listing reads 2015-2026 in the title and 2015-2025 in the bullets, and the Lo Pro's Ranger listing names 2024 in its title and 2024-2025 in its fitment line. When they disagree, ask the seller before you order.

A worked example: a 2022 Sierra 1500

Say your tape reads close to 70 in along the rail. Here's how that turns into a listing.

1. Generation. A 2022 is a T1XX, so the 2019 LD question doesn't apply. If the badge says Sierra 1500 Limited, the T3's listings name the 2022 Limited as a fit.
2. Bed. 70 in sits right on the short bed's 69.9 in and about 9 in short of the standard bed's 79.4 in. On a steel bed, a short-bed listing is a candidate whether it says 5 ft 8 in or 5 ft 10 in.
3. Bed material. A CarbonPro composite bed takes the CarbonPro listing, which BAK's Revolver X4s calls 5 ft 9 in (68 in). The Sentry CT's standard short-bed listing says it won't fit CarbonPro, and the T3 rules it out too.
4. Tailgate and boxes. With a MultiPro or Multi-Flex tailgate, pick a listing that says it works with one, as the Sentry CT's does. With a power tailgate or factory side storage boxes, the T3 is out.
5. Read the bullets, then order. Check the years and restrictions in the bullets against your truck, not just the title.

Mistakes that send covers back

• Ordering without measuring. It costs nothing, and a few minutes with a tape beats a return or a resale.
• Measuring to the wrong place. Running to the outside of the tailgate can add several inches, by RealTruck's account, and the floor gives you a mat's figure, not a cover's.
• Assuming your last truck's cover fits. A new model year can change the rails even when the bed name stays the same, as the 2024 and 2026 Ranger show. Buy the part listed for the truck you have now.
• Trusting a nickname. One Gen14 owner calls the short bed 5 ft 5 in, a name no cover listing we've confirmed uses. Your tape and the listing's inch figure are the only numbers that count.
• Reading only the title. RamBox, CarbonPro, rail systems, power tailgates and storage boxes usually show up in the bullets.

Before you order

Have five things in hand: the model year, your tape reading, the bed it points to, the rails and tailgate your truck has, and the listing's bullets. If all five line up, buy it. If one doesn't, message the seller before you order, and get the answer in writing.