Last updated: September 12, 2026
Short answer: your van’s width decides your layout, not its length. Only a Ram ProMaster is wide enough for most adults to sleep crosswise without flaring the walls (about 70 in. of usable width after insulation). Sprinters and Transits need flares or a lengthwise bed. Length decides whether you get both a galley and a bathroom.
Most layout galleries show a finished van and let you guess whether it would work in yours. This one goes the other way: it starts from the interior dimensions of each platform, subtracts what the build actually eats, and tells you which layouts survive. Measure your own van before you cut anything — trim level, year, factory liner and floor covering all move these numbers by an inch or two.
Quick answer: Our top pick in 2026 is the Ram ProMaster 136" WB, high roof — our #1 rated choice. See the full ranked comparison, alternatives and buying advice below.
- Real interior dimensions by van size
- The crosswise bed test: the measurement that drives everything
- Where the wheel wells break your cabinets
- Standing height by roof option
- Van layout ideas matched to van size
- Fixed bed vs convertible: decide by garage, not by bed
- Galley vs bathroom in a short wheelbase
- Before you build: measure, then mock up
- Frequently Asked Questions
Real interior dimensions by van size
These are approximate bare-metal cargo dimensions behind the front seats. Treat them as a starting point, not gospel.
| Van and configuration | Cargo length (approx.) | Max width | Width between wheel wells | Floor-to-ceiling |
|---|---|---|---|---|
| Ram ProMaster 136″ WB, high roof | ~126 in. | ~75.5 in. | ~56 in. | ~76 in. |
| Ram ProMaster 159″ WB, high roof | ~158 in. | ~75.5 in. | ~56 in. | ~76 in. |
| Ram ProMaster 118″ WB, low roof | ~106 in. | ~75.5 in. | ~56 in. | ~65 in. |
| Mercedes Sprinter 144″ WB, high roof | ~130 in. | ~70 in. | ~53 in. | ~76 in. |
| Mercedes Sprinter 170″ WB, high roof | ~173 in. | ~70 in. | ~53 in. | ~76 in. |
| Ford Transit 148″ WB, high roof | ~144 in. | ~70 in. | ~49 in. | ~81 in. |
| Ford Transit 148″ WB, medium roof | ~144 in. | ~70 in. | ~49 in. | ~72 in. |
| Ford Transit 130″ WB, low roof | ~126 in. | ~70 in. | ~49 in. | ~57 in. |
| Minivan (Sienna, Odyssey, Pacifica) | ~100-120 in. flat floor | ~60 in. | ~46-49 in. | ~38-40 in. |
Now subtract the build. A normal wall assembly — furring strips, an inch of insulation, thin plywood or tongue-and-groove — costs you roughly 2 to 2.5 in. per side, so 4 to 5 in. of width total. A subfloor with insulation and finish flooring costs 1.5 to 2.5 in. of height, and a ceiling with insulation and panel costs another 1.5 to 2 in. That is the number that matters, not the brochure figure. If you are still choosing materials, the thickness trade-off is covered in our guide to choosing van insulation that does not steal interior space.
The crosswise bed test: the measurement that drives everything
See also: Gifts for Van Lifers: Small, Useful and Actually Wanted • Van Toilets Compared: Composting, Urine-Diverting, Cassette and Bucket
Sleeping across the van instead of along it buys you 2 to 4 ft. of floor, which is the difference between a real kitchen and a camp stove on a milk crate. Whether it fits is simple arithmetic: your height plus about 2 in. of wiggle room must be less than the usable width at mattress level.
- ProMaster: about 75.5 in. bare, roughly 70-71 in. after a thin wall build. Most people up to about 5’10” sleep crosswise comfortably. This is the ProMaster’s one genuine advantage and it is a big one.
- Sprinter and Transit: about 70 in. bare, roughly 65-66 in. after walls. That is a fit for someone around 5’4″ and a compromise for anyone taller. Honest answer: a 6-ft adult does not fit crosswise in an unmodified Sprinter or Transit. Do not design around it.
- With wall flares: bolt-on or bonded flares add roughly 4 to 6 in. per side at bed level, which pushes a Sprinter or Transit to 74-78 in. usable. That makes a crosswise bed real, at the cost of money, a permanent body modification and a leak path you now own forever.
- Minivan: no. At 46-49 in. between the wheel wells, the bed runs front-to-back with your feet under the front seats.
One more catch: the walls of all three big vans curve inward as they rise. Measure at the height your mattress will actually sit, not at the floor. A bed platform at 38 in. often measures an inch or two narrower than the floor does.
Where the wheel wells break your cabinets
Wheel wells are the reason so many builds look awkward at the back. They intrude 6 to 10 in. into the floor on each side and stand roughly 10 to 13 in. tall, and they land under the rear third of the van. You get three options: build the bed platform above them so they vanish into the garage, break the lower cabinet run and use the well as a step or seat base, or run a continuous countertop over them and lose the floor cabinet underneath.
Running the galley forward of the wheel wells and putting the bed over them is the cleanest answer in almost every layout. If you fight it — a full-height fridge cabinet landing right on a wheel well, for instance — you end up with a cabinet that is 10 in. shallower than the rest and looks like a mistake. Plan the galley cabinet run around that break from the start.
Standing height by roof option
A high-roof Transit gives the most headroom of any factory van — roughly 81 in. bare, which still leaves 76-78 in. after a full floor and ceiling. High-roof Sprinters and ProMasters land around 76 in. bare and 71-73 in. finished, meaning a 6’0″ person stands up but a 6’2″ person ducks slightly. Medium-roof Transits at about 72 in. bare give you 67-68 in. finished: sitting headroom, not standing. Low-roof vans and minivans are sit-and-slide builds, full stop, and that is a legitimate choice if stealth and parking matter more than comfort.
Van layout ideas matched to van size
| Layout | Minimum van that works | What you get | What you give up |
|---|---|---|---|
| Crosswise fixed bed + galley + garage | ProMaster 136″ high roof | Full kitchen, large garage, bed always made | No indoor bathroom without shrinking the galley |
| Crosswise bed + galley + wet bath | ProMaster 159″ or Sprinter 170″ with flares | Everything, comfortably | Length, cost, harder city parking |
| Lengthwise fixed bed along one wall | Sprinter 144″ / Transit 148″ high roof | Standing height, galley opposite the bed | Narrow aisle, bed is 24-30 in. wide |
| Convertible dinette-to-bed | Transit 130″ / ProMaster 118″ | Seating for guests, daily-driver feel | Making the bed every night; no garage |
| Sit-and-slide platform | Minivan, low-roof cargo van | Stealth, fuel economy, cheap build | No standing, cooking happens outside |
Fixed bed vs convertible: decide by garage, not by bed
The fixed-bed argument is rarely about the mattress. It is about the garage underneath it. A bed platform at 36-40 in. gives you 28-34 in. of clear garage height, which swallows two bikes with the front wheels removed, a portable toilet, tools and water tanks. A bed at 30 in. gives you roughly 22-24 in. — bins and a folding bike, nothing upright. If bikes are the whole reason you are building the van, set the garage height first and let the bed follow; you can lose an inch back by sleeping on a 4-in. mattress instead of 6-in.
Convertibles make sense in short-wheelbase vans and minivans, where a fixed bed would eat the only usable floor. The honest cost is the nightly ritual, which pushes most people to a fixed bed by year two. Whichever you pick, the platform needs to carry load without flexing — our notes on building a bed platform that does not sag cover span and support spacing.
Galley vs bathroom in a short wheelbase
In a 136″ ProMaster or a 144″ Sprinter you have roughly 10 to 11 ft. of usable length. A crosswise bed takes about 6 ft. of that including the mattress and the frame overhang. What is left is 4 to 5 ft. of floor, and a usable wet bath needs 30 to 34 in. of it. Put both in and the galley becomes a 24-in. countertop with a single burner and a portable cooler.
Most people who build short and then rebuild go one of two ways: a full galley with a cassette toilet in the garage and showers taken outside, or a compact wet bath with a tiny galley and the acceptance that most cooking happens at the side door. There is no third answer at that length — the inches simply are not there. If you are undecided, read the trade-offs in our comparison of campervan toilet setups and the practical realities of plumbing a van water system before you frame anything.
Before you build: measure, then mock up
Tape your layout onto the bare floor with painter’s tape and live with it for a week. Sit where the bench will be. Stand where the counter will be. Lie down where the bed will be with the doors closed. Almost every layout regret — a counter that blocks the slider, a bed you cannot sit up in because the wall curves, a garage 2 in. too short for the bike — is visible in tape and invisible on paper. It is also worth sanity-checking weight distribution and payload at this stage, since a rear-heavy build is a real problem covered in our guide to what a van build actually costs and weighs, alongside the electrical system sizing that usually lands under the bed.
Frequently Asked Questions
Can a 6-foot person sleep crosswise in a Sprinter?
Not without modification. A 144″ or 170″ Sprinter gives about 70 in. of bare interior width, and a normal insulated wall build leaves roughly 65 to 66 in. at mattress height. That is several inches short for a 6-ft adult. Adding bolt-on wall flares gains about 4 to 6 in. per side and makes it work, but flares are a permanent body modification with a real cost and a new leak path to maintain. The alternative is a lengthwise bed or a diagonal corner bed.
What actually fits in a ProMaster 136 high roof?
A crosswise fixed bed for most adults, a galley of roughly 4 to 5 ft. with a sink, two-burner stove and a 12V fridge, a garage about 30 in. tall under the bed, and a portable toilet stored in that garage. What does not fit comfortably is a dedicated wet bath alongside a full galley — you can have one or a compromised version of both. Measure your own van, as floor covering and trim vary.
Which van has the most standing headroom?
The high-roof Ford Transit, at roughly 81 in. of bare floor-to-ceiling height, which still leaves about 76 to 78 in. after a typical insulated floor and ceiling. High-roof Sprinters and ProMasters sit around 76 in. bare and finish near 71 to 73 in., so anyone over about 6’1″ will be ducking slightly. Medium-roof Transits at roughly 72 in. bare do not give standing height once the build is in.
How tall does the garage need to be for bikes?
Plan on 28 to 34 in. of clear height under the bed platform for two bikes with the front wheels removed, laid on their sides or stood on the rear wheel depending on frame size. Under about 24 in. you are limited to bins, folding bikes and gear. Measure your specific bike with the wheel off rather than trusting a general number, because tall frames and long-travel mountain bikes can need several inches more than a road bike.
Is a minivan conversion worth it, or should I just buy a cargo van?
A minivan is worth it if stealth, fuel economy and using the vehicle as a daily driver matter more than standing height and a fixed bed. You get roughly 100 to 120 in. of flat floor and about 38 to 40 in. of height, which supports a sleeping platform with storage underneath and a slide-out kitchen used at the tailgate. If you want to cook, shower or stand inside, no amount of clever layout fixes a minivan and you want a high-roof cargo van.
Ready to decide? Our #1 pick for 2026 is the Ram ProMaster 136" WB, high roof.
Live price & availability on Amazon.
