How to measure a truck bed

Measure inside the box, at the floor, from the inside face of the bulkhead to the inside of the closed tailgate. That tape figure is your bed length. On current full-size pickups it lands in one of three bands (roughly 65 to 70 inches, 76 to 82, or 96 to 98) and almost no bed measures what its badge calls it.

Where to put the tape

Latch the tailgate. Hook the tape on the bed floor against the bulkhead (the front wall of the box, behind the cab) run it down the centre of the floor, and read it where the closed gate meets that floor. Record inches; feet are where rounding errors start. That floor figure is what every parts catalogue, cap maker and tonneau configurator is built around.

Four ways people get it wrong:

• Outside, along the bedside. You pick up panel thickness at both ends and read long.
• Along the top of the rail. On a raked bulkhead the rail and the floor are different lengths, and the floor is the published spec.
• With the tailgate down. That is a loading length, not a bed length.
• Over a drop-in liner. It takes a fraction off every dimension. Pull it, or note that it is in.

How long is a truck bed? Three lengths, and the names are nominal

Trucks are sold with a short, standard or long box, and those names are rounded class labels, not measurements. A bed badged 5.5 feet should be 66 inches and measures 67.1; GM's 5'8" box measures 69.9. What the manufacturers publish for cargo box floor length on the generations we stock deepest:

Those figures are generation-specific: floors, wheelhouse spacing and rail profiles changed at every redesign, which is why a cap off a 2014 truck rarely sits right on a 2019 one. Midsize goes shorter again: the current Tacoma's 5-foot box is about 60 inches, its 6-foot box about 73.5.

How wide is a truck bed? Two widths, one constraint

Every bed has a wide measurement at the floor and a narrow one between the wheelhouses. The narrow one decides what fits. A 2019-2026 Silverado 1500 box is 71.4 inches across the floor at its widest and 50.6 between the wheel wells.

A 4x8 sheet is 48 by 96 inches. At 50.6 inches the F-150 and the GM half-tons take it flat, the Ram's 51.0 is the most generous here, and the Tundra's 48.7 clears a sheet by about three-quarters of an inch in total, enough on paper, not enough to slide in without touching a wheelhouse. The 96-inch length then needs the long box.

How deep is a truck bed?

Between 20.9 and 22.4 inches across every truck above: 22.4 on a current Silverado 1500, 21.1 on a Super Duty. Depth decides whether a load sits below the rails, which decides whether a tonneau will close over it.

Dropping the tailgate adds roughly the depth of the bed again in usable floor, call it 20 inches on a half-ton, and measure your own gate because it varies. That is how a 6.5-foot box carries 8-foot lumber. It is not a bed length.

How to measure a truck bed for a cover

A cover is not ordered in inches. Tonneau covers and caps clamp to one specific truck's rails, so the configurator wants year, make, model and bed length, bed length as a name, not a number. Your tape's only job is to tell you which of your model's boxes you have, the step crew-cab owners miss because one crew cab is often offered with two boxes in the same year.

Match the floor figure to the nominal name, then check four things before ordering a tonneau cover or a truck cap or camper shell:

• Liner type. A drop-in liner that wraps over the rails eats the clamping surface. Under-rail and spray-in liners do not.
• Factory track or cargo-management system in the rail channel. Some covers mount to it, some need it out, and tie-down pucks often sit where a clamp goes.
• Aftermarket rail caps which add height and change clamp geometry.
• Bed style: fleetside or stepside. Nothing crosses that line.

How wide is a pickup truck?

Different question. Bed width is interior; truck width is exterior. A current full-size half-ton runs roughly 80 to 82 inches across the body without mirrors and about 96 inches across standard mirrors extended. A single-rear-wheel Super Duty is about 80 inches across the body; the dual-rear-wheel version is 96 inches across the rear fenders. Mirrors catch garage frames and canopies; rear fender width decides whether a dually fits between a car trailer's fenders.

What is a fleetside bed?

Fleetside is Chevrolet's name for the smooth-sided bed with the wheel wells inside the box, the ordinary pickup bed. Every maker named it differently: GMC called it Wideside, Ford calls it Styleside, Dodge called it Sweptline. The narrow alternative, wheels outside the box in separate fenders with a step behind the cab, was Stepside at Chevrolet, Fenderside at GMC, Flareside at Ford, Utiline at Dodge.

Almost every pickup built today is a fleetside or styleside, so sellers use the word loosely to mean the standard bed. Buying used, it stops being loose: a stepside truck bed or box, its bedsides, its fenders and its cap do not interchange with fleetside parts, and the two differ in width at the same nominal length.

How to tell which bed you have without a tape

The tape is the honest answer, but there are cross-checks. The window sticker or build sheet names the box. GM trucks carry a service parts identification label, usually in the glovebox, listing a box code among the option codes, and any dealer parts desk can read box length off a VIN in seconds. For a specific part rather than a whole bed, the fastest route is the interchange number, which groups parts that are the same stamping across years and models. Cab configuration is a hint, not proof: crew cabs skew short, regular cabs long, and a Silverado 1500 crew cab was sold with two boxes in one model year. Measure before you spend.

Five things to write down before you buy a bed, cap or cover

• Year, make and model.
• Cab: regular, extended or crew.
• Measured floor length in inches, gate closed, liner noted.
• Bed style: fleetside or stepside.
• Single or dual rear wheel.

Send those five and we will tell you what fits. Most of what we hold is used, pulled from damaged trucks here in Toledo and photographed as it is, dents and paint drift visible; the new aftermarket and OEM stock is listed as new, and never the other way round. Beds, caps and tailgates move by freight, shipping is included in the listed price, the warranty is 90 days parts only, and returns run 30 days with no restocking fee. What we do not do is fit it: a bed swap is a shop job or a weekend with help, a hoist and new bolts, and that labour is not ours to quote.

Questions we get about bed measurements