Nearly everyone viewing a space for a CrossFit box opens with the square metres. It's the figure in the listing, the one you weigh unit against unit, the one that sets the rent — and it's the one that disqualifies the fewest places. What tends to knock a unit out isn't the floor it offers but the roof above it. If you've already got your head round what CrossFit is and the question is now where to put it, these are the numbers to take with you.
There's an order to it, too, because the figures don't weigh the same. Clear height comes first, since it's the one thing you can't put right later: you don't lift a roof or raise the beams. The usable metres come next, with some give depending on how you carve up the zones. The layout comes last — the part where a considered box earns its keep from every metre and a rushed one throws metres away. This piece works through them in that order and finishes with what to have jotted down on the day you walk the unit.
01How much floor space a CrossFit box needs
There's no one right floor area, because a village box running a single lunchtime class and a city box turning over sessions on the hour share almost nothing. What there is, is a per-person figure, and the rest falls out of it: the capacity, how many classes you can run at once and, ultimately, the numbers at the bottom of the page. Get it wrong and no fit-out rescues it — only a move does.
The usual slip is to reason like a machine gym, where members take it in turns at a station and a hundred of them sit happily in a hundred metres because they're never all moving together. A box flips that: the whole class hits the same movement in the same minute. Squat jumps in the WOD and all twelve leave the floor together; wall balls and all twelve throw together. The space isn't shared across the hour — it's wanted whole, all at once.
Square metres per athlete at peak
The working figure for planning is six to eight usable square metres per athlete (about 65–85 sq ft) in the busiest class of the day, and facility-design guidance stretches to nine or ten once the class is high-intensity, with barbells and explosive work. The word doing the lifting is "usable": clear floor, where someone can drop for burpees, set a bar down or string kettlebell swings together without catching the person beside them. Walls, the front desk, the corridor to the changing rooms and the strip the wall racks occupy don't count.
That band isn't fussiness about safety; it's about how the room feels. Below six metres a head, the clashes start — a movement gets clipped short to dodge a neighbour, the coach loses sight of half the floor, and scaling falls over because there's simply no room for the long version of a movement. A tight box announces itself in the first session and gets paid for in the third-month cancellations.
And the sum is always run against the peak hour, never the average. Four people at eleven in the morning is neither here nor there: if the six o'clock class brings in twelve, the floor has to carry twelve in comfort. Planning to the average is the quickest route to being short of space in exactly the hours that cover the rent.
What a class of twelve actually takes
There's no official figure here, and it's worth being sceptical of anyone who quotes one as if there were. The method is the only firm bit: take the metres per athlete and multiply by your busiest class. On the quick seven-to-eight metres a head, a class of twelve lands at roughly seventy to a hundred and twenty square metres of clear floor (about 750–1,300 sq ft), depending on intensity; on the nine or ten from the design guides it drifts towards a hundred and twenty. In the real world there are boxes fitting twelve into sixty metres and getting away with it, at the cost of being tighter and staggering the movements. The square metres don't decide whether you can open — they decide how good it feels.
Onto that goes everything that isn't training floor: the rack structure and the lifting platforms, the shelving wall for small kit, the front desk, the changing rooms and the routes people walk. That rarely comes in under fifty or sixty metres, and in a box with two WCs and a little shop it's a good deal more.
Put floor and back-of-house together and a box built for one class at a time sits between about a hundred and twenty very tight metres and a hundred and eighty comfortable ones; genuine slack to overlap classes or grow only appears between two hundred and three hundred. You can open under that, as long as you know the trade: the room shrinks in the first winter, when everyone's training indoors at once, and then it's either cap the numbers or drop half the timetable. Far better that sum lands before you sign than after.
02Clear height, the real filter
If floor area is the figure everyone fixes on, clear height is the one that actually sorts the workable units from the rest. It's also the only one with no remedy: a unit short on floor can be reorganised, but a low ceiling stays a low ceiling for good.
There's a measuring trap here that catches people out. The height that matters isn't the one on the drawing or the title deed, but the true clear height: floor to the lowest thing hanging overhead. In a warehouse the lowest point is hardly ever the ceiling itself — it's a beam, an air-con duct, a cable tray, a pendant light. A roof at six metres means nothing if the beams drop to three and a half; the beam is the number.
What the wall ball and the rope demand
The wall ball is the one that surprises people. The ball goes to a target set at 2.74 m (9 ft) for women and 3.05 m (10 ft) for men, but that isn't the height the room needs: the ball travels above the target, you release with arms extended, and a tall athlete starts the throw already close to the ceiling. For it to feel natural — no flinching on every rep — the usable height of that zone works out around four metres (about 13 ft).
The rope asks for more. A regulation climb is 4.5 m (15 ft) of rope, anchored to something above it. If the box is going to programme rope climbs — and nearly all do — the corner where it hangs wants to be pushing five metres of clearance. The saving grace is that it doesn't drag the whole unit up to five metres; only the strip holding the rope has to get there.
Add to that the pull-up rig, fixed up high with half the session hanging off it. It doesn't want the rope's height, but it does dictate where it can sit, since it has to anchor to something solid and leave room beneath to hang at full stretch without the feet brushing the floor.
Handstands and rings
Inverted and ring work take the height in quieter but no less real ways. A muscle-up on the rings needs clearance to hang at full stretch and then haul the whole body above them, so the rings sit high and want air below. And the work upside down — the handstand, walking on the hands, the handstand press-up against the wall — takes exactly the height of a person flipped over, plus the margin not to clip the ceiling with the feet.
Out of all that comes a handy layout rule: the whole room doesn't need the same height. The floor-level class zone and the sled lane manage on a lot less; the one that calls the shots is the high strip, where the rope, the rings and the overhead barbell work bunch up. Four good clear metres take almost all the overhead work; add rope climbs and that strip wants five. If it can't reach that anywhere, no clever zoning saves the unit — it's out, whatever floor it boasts.
03Splitting the room into zones
A box that works isn't an open shed with the kit heaped in a corner and the class on what's left. It's a room carved into three or four zones with separate jobs that mustn't tread on each other, set down in an order that makes sense: heaviest and most fixed first, giving way to the lighter and more movable. The fine detail — what sits on which wall, the colour of the room, how it photographs — is a separate chat, the one in how to plan a modern gym design; here we're on the big blocks and on keeping them out of each other's way.
Racks and platforms
The strength zone anchors the whole layout, which is why it goes down first. It sits against a solid wall or in a central frame and gathers the squat racks, the barbells, the plates and the platforms where the weight gets dropped. It's the heaviest, the loudest and the least likely to move once built, so the rest of the room arranges itself around it rather than the reverse.
Each lifting station wants about two metres by two to work safely — a full lifting platform is roughly that footprint — plus the clearance behind so nobody walks through as a loaded bar comes down. Capacity sets the number of platforms: for a class of twelve with a shared strength block, don't drop below six to eight stations unless you want people queuing mid-session. And that zone's kit — plates, collars, spare bars — lives right there, not across the room.
The sled lane
The sled lane wants the opposite of the racks: not height, but clear length. A lane worth having is twelve to twenty straight, clear metres (about 40–65 ft), with no column mid-run, no rack eating the far end and nothing to drag aside before you push. A metre to a metre and a half across per lane does the job, but the length is the non-negotiable: a sled over ten metres is a gesture, not a piece of work. It's the single thing most often forgotten on a floor plan, and the one that most dictates the surface — more on how the body actually works it in sled push technique.
Storage and flow
Small kit — kettlebells, dumbbells, boxes, skipping ropes, balls, bands — wants its shelving wall, not a corner where it mounds up and never goes back. A tidy box stores upright, keeps the floor for training and turns the reset between classes into a one-minute job rather than ten. It reads as an afterthought and it's anything but: it's what keeps the room usable when sessions run back to back.
Then there's flow, the invisible part of the layout: the route people take to come in, drop a bag, fill a bottle and reach the changing rooms without cutting across the class zone. Run that route through the middle of the floor and every latecomer interrupts a WOD of twelve. A well-laid box pushes the flow to the edges and leaves the middle clear for training.
04The floor, zone by zone
There's no one floor that suits the whole box, and holding out for one is the costliest mistake, because it only shows once everything's down. Each zone loads the floor differently, and asking a single material to cope with the lot ends in a surface that does none of it well.
The barbell zone wants thick rubber, in the two-to-four-centimetre range, to soak up the plate drop and protect the slab beneath. No debate there: anything else cracks, bounces the weight or drives the shock into the structure. It's a pricey, heavy floor, which is precisely why you pin it to where the bar actually lands rather than rolling it across the unit.
The class, warm-up and sled zone wants the reverse: a surface that slides evenly the length of the lane, won't take skin off on a burpee, shrugs off the sled's constant drag and lets you plant a hand without a second thought. That's the natural home of artificial turf for your box, and it's what makes an indoor sprint lane possible in the first place. Thinking that split through at the start, rather than once the racks are bolted down, is part of what tells a well-built box from one that's ripped up two years in.
05Seen in the wild: the Testa Training track
All of the above — zones that don't clash, the lane and its length, the floor planned by use — lands better with a real box in front of you. Testa Training, a training centre in Santa Cruz de Tenerife, came to us with a plain problem: it needed a surface that could take what they genuinely do every day — sled pushes, jumps, burpees and high-intensity sessions — and keep its grip session after session. The kit was already in; what was missing was the floor to carry it.
What we built is a 6 × 12 metre hybrid track, designed, manufactured and fitted by us and fully bespoke. It holds six sled lanes side by side, each with 1.80 metres of run-up to pull and push: six athletes dragging at once, in parallel, with no waiting for a turn and no straying into the next lane. The finish is in the Valhalla colour, with the centre's logo and the technical markings set into the turf — not stuck on top — which is what keeps every session tidy and every rep where it belongs.
And it's no single-trick track, which is the whole point. The same surface carries the daily sled pushes but also the burpees, broad jumps and lunges of the class, rep after rep, because it slides evenly, won't burn skin and takes the constant drag. As the centre sums it up: "It changed the way we train. Sleds, jumps, high intensity — you need the lot, every day, and it still feels unreal." The full project, with photos, is on the Testa Training page.
06What to measure before you sign
CrossFit box dimensions aren't settled on a drawing but in the unit, tape in hand. Before you sign a thing, go and come away with five numbers written down. They aren't everything you need to open, but they're the ones that rule out a poor unit before you fall for it:
- The true clear height, taken to the lowest thing hanging overhead — beam, duct, light — never to the roof. A single beam dropping to three and a half metres right where the rope was going to hang is your height, not the rest of the unit's.
- The usable metres, less the pillars, the columns, the front desk, the changing rooms and the floor the storage will swallow. The listing quotes gross area; what matters is what's left clear to train on.
- A straight run of at least twelve metres with nothing in the way (fifteen to be comfortable), to see whether the sled lane fits in some orientation of the room. If it fits in none, the sled's out — better known now than later.
- The state of the slab, because on a floor that's out of level no surface sits right or lasts, and re-levelling a whole unit costs almost what the new floor does.
- Where the light gets in and how the air moves, which no tape measures but which decide whether training feels good in July and in January. A unit with no cross-ventilation is an oven come summer, whatever its metres.
With those five in hand you'll know whether a unit suits your box before the listing's square metres turn your head — which is exactly the figure that tells you least.
07In short
A CrossFit box is judged in a set order: height first, because it's the filter with no fix and the one that bins units that looked ideal on paper; usable metres next, at six to eight per athlete at peak (more for a high-intensity class); and the split into non-clashing zones last.
The critical height strip is the rope, the rings and the overhead barbell: four good metres for almost everything, five if there are rope climbs. For a class of twelve to breathe, reckon on roughly seventy to a hundred and twenty metres of clear floor by intensity — and plenty of boxes run on less — while the whole unit, with back-of-house, rarely feels roomy under two hundred metres. The sled lane wants length, not height, and each zone wants its own floor: thick rubber where the bar lands, turf where you slide, sprint and go to ground.
If you're weighing up a unit and want to know whether your metres and your height stack up for the box in your head, get in touch and we'll look at it against your real measurements before you sign. And to carry on with design and fit-out, it's all on our facility-design blog.
