To measure a cargo area, empty it, set the seats and floor the way you actually use them, and record three numbers inside its main boundaries: depth, width and height. Then measure the opening separately and note the wheel wells, slopes and latches that break up the floor. A tape measure, a notepad and about ten minutes are enough.
This guide covers the full method for SUVs, hatchbacks, wagons, minivans and sedan trunks. It also explains what to write down if you are choosing a cargo liner, because a liner follows the shape of your floor, not just its length and width.
TL;DR
- Measure depth, width and height inside the cargo area’s main boundaries, with seats and adjustable floors in a fixed, known position.
- Measure the opening on its own. The narrowest point of the opening, not the interior, decides what fits through.
- Record width at its narrowest point (usually between the wheel wells) and add a small margin of about 1 inch for anything you plan to fit.
- Measure with the rear seats upright and again with them folded, and write down both sets.
- For a cargo liner, you do not need exact interior numbers. Your year, make, model and trim identify the laser-measured pattern, and your measurements are a cross-check.
Table of Contents
- What you need before you start
- Fix the variables first
- Measuring depth, width and height
- Measure the opening separately
- Wheel wells, slopes and other irregular shapes
- Seats folded, seats up
- Turning measurements into cubic feet
- Allow a margin
- What to record if you are buying a cargo liner
- Perspective: what we see in cargo measurements
- Protect the floor you just measured
- Common mistakes to avoid
- FAQ
- Sources
What you need before you start
Keep the kit simple:
- A rigid or locking tape measure, 12 feet or longer. A soft sewing tape sags over long spans and gives you readings that are too generous.
- A notepad or a phone note. Write every figure down as you take it, with a label.
- A flashlight for dark corners and under-floor compartments.
- A helper, if the cargo area is long. One person holding the tape at the far end saves a lot of drift.
Empty the space completely. Remove loose items, organizers, the spare cover if it lifts out, and any existing mat. If you have a second-row bench that slides, decide now whether you measure with it forward or back, and record that choice.
Fix the variables first
Most bad measurements come from a moving target. A sliding seat, a reclining seatback or an adjustable cargo floor can each change your numbers by several inches. Cars.com, which publishes its own cargo measuring method, handles this by setting sliding seats rearward, reclining seatbacks to a standard angle and adjustable cargo floors to their lowest position before it measures.
You do not need to copy that exactly, but you should pick a configuration and stick with it:
- Decide whether you want to know the space with the rear seats up, folded, or both.
- Put adjustable floor panels at the height you will normally use. If you want the maximum depth for tall items, set it to the lowest position.
- Slide second-row seats to the position you drive in, not the one that looks best on paper.
- Write the configuration at the top of your notes.
Measuring depth, width and height
The core method is straightforward. Cars.com describes it as measuring depth, width and height within the cargo area’s major boundaries, with nooks outside that main space accounted for separately. Here is how that looks in practice.
Depth (length)
Run the tape along the floor from the inside edge of the opening, meaning the sill where the floor meets the hatch or trunk lid, to the back of the rear seatback. Do this along the centerline. Then do it again near each side, because the seatback is rarely a perfectly straight wall. If the floor slopes upward toward the seats, follow the floor surface rather than measuring in a straight line through the air, and write down which one you did.
Width
Measure side to side at two points: the widest spot, usually toward the front near the seats, and the narrowest, which is almost always between the rear wheel wells. The narrow figure is the one that matters for fit. A box, a stroller or a liner that is wider than that gap will not lie flat.
Height
Measure from the floor to the ceiling or headliner in an SUV or wagon. In a vehicle with a cargo cover or parcel shelf, measure to the underside of the cover if you keep it in place. In an enclosed trunk, measure from the floor to the top of the trunk opening, as Cars.com does for sedans. For hatchbacks, a useful figure is the height up to the window line, since stacked items that touch the glass will slide when you brake.
A quick record sheet
Copy this into your notes:
| Measurement | Seats up | Seats folded |
|---|---|---|
| Floor length, center | ||
| Floor length, left side | ||
| Floor length, right side | ||
| Width, widest | ||
| Width, between wheel wells | ||
| Height, floor to ceiling or window line | ||
| Opening width, narrowest | ||
| Opening height, lowest |
Recording the left, center and right sides is not fussiness. It is how you capture the asymmetry caused by wheel wells, seat rails and trim, which is the main reason a flat mat that looks big enough still leaves gaps.
Measure the opening separately
The space inside a vehicle can be generous while the way in is not. Sedan trunks are the classic case: the trunk mouth is narrower than the compartment beyond it. Hatchbacks and SUVs have their own pinch points, such as a bumper lip that rises into the opening or a liftgate frame that cuts into the usable height.
Consumer Reports builds this into its testing. It says a small cargo opening can limit what you can carry, and it tests the largest box that fits through the opening and into the cargo area with the hatch closed. You can borrow the same logic at home:
- Measure the narrowest width of the opening, at the point where the frame or hinges come closest together.
- Measure the lowest height, from the sill to the lowest edge of the lid or liftgate frame when open.
- Compare the item against those two numbers first. Only then check the interior figures.
If you are carrying something stiff, such as a flat-pack bookcase, a folded liner or a wheeled cooler, the diagonal can help. Tilting an item on an angle often gets it through a smaller opening, but only if the interior height allows the turn.
The same measure-the-entrance-first habit is useful elsewhere, too. If you are sizing a storage unit to hold what comes out of your cargo area, the door and your items’ largest dimension matter as much as the floor area.
Wheel wells, slopes and other irregular shapes
No cargo area is a perfect rectangle. Here is how to handle the awkward parts without overcomplicating things.
Wheel wells. Measure floor width at its narrowest point, which is normally between the wells. Then measure how far each well protrudes into the floor and how tall it stands. If you plan to carry a sheet of plywood flat, the usable width is that between-the-wells figure, not the wide measurement behind the seats.
Sloped sides and rear seatbacks. On many crossovers the sides taper toward the roof and the seatbacks lean. Take your height reading at both the front and rear of the floor. Aim for the lowest of those numbers when you plan a load, and log the slope separately.
Folded-seat slope. With seats folded, many vehicles do not form a flat floor. There may be a step, a ramp or a gap. Measure the lowest height along that slope and record whether the floor is level. If the seats do not fold flat, usable length may be less than the tape suggests.
Under-floor storage. Lift the panel and look. If there is a spare tire well or a partitioned bin, record its depth and note whether it is part of your plan. Cars.com notes that floor gradients and partitioned under-floor space need to be accounted for in a consistent method, so decide what counts and keep it consistent.
Raised lips, handles and latches. Note anything standing proud of the floor: a raised sill, tie-down points, an access handle for a hidden compartment, seat rails. These do not change the volume much, but they change how a flat item sits and how a liner has to wrap.
Seats folded, seats up
Measure both ways. With the rear seats up, you learn the space for daily use: groceries, a gym bag, a dog crate. With them folded, you learn the space for the occasional large load.
For the folded measurement, fold the rear seats completely flat and measure from the back of the front seat to the tailgate opening. Write the front-seat position beside it, because moving the driver’s seat forward a few clicks changes the answer.
One caution about “maximum cargo volume” numbers you see in brochures and reviews. Cars.com says it does not publish a maximum with all seats folded because too many variables make it hard to measure accurately. Your own tape measure, in your own configuration, is more reliable than a single headline figure.
Turning measurements into cubic feet
If you want a volume figure, multiply length by width by height in inches and divide by 1,728 to get cubic feet. For example, a floor 40 inches deep, 44 inches wide and 30 inches high gives 52,800 cubic inches, or about 30.6 cubic feet.
Treat that as a rough estimate. Wheel wells, slopes and fixed equipment all reduce what you can use, so a plain box calculation overstates it. And do not expect it to match the spec sheet. Open cargo areas, like those in SUVs and wagons, are measured by volume using height, width and depth, while trunk sizes are measured with luggage-like blocks under an SAE standard. The two methods give figures that cannot be compared directly, which is why a sedan and an SUV with the same listed cubic feet can feel very different.
Allow a margin
Whatever you are fitting, give yourself some breathing room. One accessory-sizing guide recommends adding a 1-inch tolerance margin to your measurements. That is a sensible habit for crates, coolers and furniture. If you are within an inch of the limit on any dimension, assume it will not fit until you try it.
What to record if you are buying a cargo liner
A cargo liner is a different job from a box. It has to follow the floor, climb the sides and sit around fixed features. So alongside depth and width, note these:
- Wheel-well intrusions on both sides.
- Seatback angle, and whether the seats fold flat or leave a step.
- Sill and latch positions at the opening.
- Raised lips, access handles and seat rails that affect fit or access.
- Whether your vehicle has a factory cargo tray, an adjustable floor or a third row.
The most important details, though, are the ones that do not need a tape: model year, make, model, trim and cargo configuration. Trims can change the floor. For example, our listing for the 2024-2026 Chevrolet Traverse cargo liner is marked as not for the 2024 Limited trim, and the 2013-2018 Toyota Avalon liner states the trims it fits. Reading those fitment lines on a product page matters more than any ruler measurement, because the pattern is built for a specific vehicle.
If you want a liner with a raised perimeter to contain spills, our guide to raised lip cargo liners shows how the main options compare, and measuring the height of the area around your floor tells you how much lip your cargo space can accommodate.
A worked example
Say you own a compact crossover and want to check whether a 36-inch-wide dog crate fits.
- Opening: narrowest width 40 inches, lowest height 27 inches with the liftgate open. The crate passes.
- Interior: width between the wheel wells is 38 inches. With a 1-inch margin each side, you have 36 inches. It is tight, but it works.
- Height: floor to window line is 29 inches. The crate is 25 inches tall. Fine.
- Depth: 34 inches with the seats up. The crate is 24 inches long. Fine.
Fit confirmed, and you also know the crate leaves 10 inches of floor depth, which is room for a small bag. A liner under it will protect the floor from claws, mud and the occasional accident.
Perspective: what we see in cargo measurements
We build cargo liners for specific vehicles, and the lesson we return to is that the floor is rarely as simple as it looks. Wheel wells, sill lips, seat rails and trim create a shape that a rectangle cannot cover. That is why our approach is laser-measured, custom-fit protection rather than a trim-it-yourself sheet.
Measuring your own cargo area is still worth doing. It tells you what you can carry, which items need the seats folded, and where spills tend to collect. Treat the liner as the part that carries the dirt, so that your measurements can focus on the loads.
Our products are designed to be easy to clean and made from recyclable materials, with the goal of precise coverage at a fair price. When you match your year, make, model and trim, you are choosing a liner built to the contours you just measured.
Marty
Protect the floor you just measured
Once you know your space, protecting it is the easy part. Our custom fit cargo liners are designed for specific makes and models, with coverage shaped to the cargo floor. You can browse by vehicle on the cargo liners collection, and if the rest of your interior needs the same treatment, see our custom fit floor liners. Keep your notes handy and check the fitment details on your vehicle’s page before you order.
Common mistakes to avoid
- Measuring the widest point only. The narrowest width is the one that limits fit.
- Forgetting the opening. Interior space does not matter if the load cannot get in.
- Leaving seats in an unknown position. Note it every time.
- Using a sagging tape. Long spans need a rigid tape or a helper.
- Trusting spec-sheet cubic feet for a specific item. Test the real dimensions instead.
- Ignoring the cover or parcel shelf. It lowers the height you can use.
- Skipping the trim. Two trims of the same model may have different cargo floors.
FAQ
How do I measure a trunk?
Measure the depth from the trunk sill to the back of the rear seat, the width at its narrowest point, and the height from the floor to the top of the trunk opening. Then measure the opening separately, since a trunk mouth is often smaller than the space beyond it. Write all figures down with the seat position noted.
Should I measure with the rear seats up or folded?
Both. Seats up gives you your everyday space, and folded gives you your large-load space. Fold the seats fully flat and measure from the back of the front seat to the tailgate opening. If they leave a step or slope, the usable length can be shorter than the tape reading.
How do I find cargo volume in cubic feet?
Multiply length, width and height in inches, then divide by 1,728. The result is an estimate, because wheel wells and fixed features reduce usable room. It also will not match manufacturer figures, which use different methods for open cargo areas and enclosed trunks.
Do I need exact measurements to order a cargo liner?
Not usually. A custom-fit liner is matched to your vehicle’s year, make, model, trim and cargo configuration, so choose those correctly on the product page. Measurements are a good cross-check, and they help if your vehicle has a feature that changes the floor, such as a cargo tray or adjustable panel.
How much margin should I leave when fitting an item?
About 1 inch on each dimension is a sensible allowance for boxes, crates and accessories. If you are inside that margin, test the item in the vehicle before relying on the numbers.
Sources
- How Cars.com Measures Cargo Space
- Cargo Room Actual Measured Space for SUVs, Minivans (Consumer Reports)
- Everything You Need to Know About Car Measurements and Specs (Capital One)
- How to Measure Your Car’s Cargo Space (Will It Fit?)
- Measure your car before buying accessories (GearNudge)
- What Size Storage Unit Do I Need?