TL;DR: As a quick rule, allow 1.5-2 square metres per seated guest once you've factored in tables, a dance floor and room to move. But guest count is only the start. Your layout, your dance floor, your bar and even your guy ropes all change the size you actually need.
This guide walks you through all of it, with the numbers we use ourselves when we're sizing an event. For an exact answer, we’d recommend booking a free site visit.
The quick formula for working out marquee size
Allow 0.75-1 square metre per standing guest, and 1.5-2 square metres per seated guest once tables and chairs are in.
That second figure already builds in the basics. But tables, flooring, a catering area, a bar and room for people to move can push your total space up by another 30-50%, so don’t treat the formula as your final number. Whatever your seating calculation gives you, add at least 20% on top.
The type of event also matters as much as the headcount, which is where layout comes in.
Layout changes the size more than you think
The same 100 guests need very different amounts of space depending on what they're doing. Here's how the three main layouts compare.
| Layout | Space per guest | Best for |
|---|---|---|
| Cocktail (standing) | 0.7 sq m | Standing events of 2 to 3 hours |
| Theatre (ceremony) | 0.9 sq m | Ceremonies, presentations, short structured events |
| Banquet (seated dining) | 1.2 sq m, plus 20 to 30% | Weddings and seated dinners |
Cocktail is the most space-efficient. Everyone's standing, so you fit the most people into the smallest footprint.
Theatre sits in the middle: seated, but no tables to work around.
Banquet needs the most of all, because you're accounting for tables, chairs, service aisles and space for a band or dance floor. It's also the standard for weddings, which is why weddings need more space than people expect.
What size marquee do you need for your guest count?
These are the sizes we'd recommend for a full seated event with dining and dancing, which is the setup most weddings need.
| Guests | Space needed | Recommended marquee | Notes |
| 50 | ~55 sq m (ceremony) | 9x9 m for dinner and dancing | A 6x9 m fits tables only, no floor or bar |
| 100 | 90 to 150 sq m | 10x15 m | A 9x12 m leaves no room for a dance floor |
| 150 | 200 to 220 sq m | 15x15 m | Multi-zone layouts need more again |
| 200 | 280 to 300 sq m | 15x21 m | Plan for multi-day install and large vehicle access |
Marquee for 50 guests
A 50 guest wedding with dining and a dance floor needs a 9x9 metre marquee. For a ceremony on its own, around 55 square metres is plenty, which a 6x9 covers.
A 6x9 marquee holds the tables for a sit-down meal and nothing else, no dance floor, no bar. We've had couples book on the numbers alone and only realise at the site visit that there's nowhere for anyone to dance. If you want dancing, go to the 9x9.
Marquee for 100 guests
A 100 guest wedding with dining and dancing needs a 10x15 metre marquee, somewhere between 90 and 150 square metres, depending on your layout.
The 9x12 is the mistake we see more than any other. Someone books it because the numbers technically fit, and they do, just barely, with minimal spacing and no room for a dance floor or bar. Then the band turns up on the day and there's nowhere to put them, and once the marquee's up there's no fixing it.
For 100 guests who'll eat and dance, it's a 10x15, and for a wedding we'd always tell you to size up rather than work to the minimum.
Marquee for 150 guests
A 150 guest seated wedding with dining and dancing needs a 15x15 metre marquee, around 200 to 220 square metres. If you're splitting the space into separate zones for dining, a bar and dancing, add more on top of that.
Marquee for 200 guests
A 200 guest wedding needs a 15x21 metre marquee for a full banquet layout, roughly 280 to 300 square metres. At this scale the logistics matter as much as the size, so plan for a multi-day install and access for large delivery vehicles.
Standard marquee sizes in the UK
Here are the standard marquee sizes and what each one suits.
| Marquee size | Floor area | Guests | Best for |
|---|---|---|---|
| Up to 6x6 m | 9 to 36 sq m | 10 to 50 | Garden parties, intimate gatherings |
| 6x9 to 10x10 m | 54 to 108 sq m | 50 to 100 | Most weddings and celebrations |
| 12x12 to 15x21 m | 144 to 315 sq m | 100 to 200+ | Large weddings, corporate events, galas |
Watch the small sizes. A 3x3 metre is really a pop-up gazebo. It's only from 4x4 up to 6x6 that you're into proper marquees.
In the medium range, the 9x12 metre is the UK's default wedding marquee, comfortably taking 80 to 100 guests with dining and a dance floor.
For smaller celebrations, our party marquee hire page covers the sizes that suit garden events. For the full setup, see wedding marquee hire.
The extras that take up more space than you think
This is where sizing goes wrong. People calculate for guests and forget everything that has to fit around them.
| Feature | Space it takes | Worth knowing |
|---|---|---|
| Dance floor, 50 guests | 3x3 m (9 sq m) | The single most forgotten element |
| Dance floor, 100 guests | 4x4 m (16 sq m) | Grows with the guest list |
| Bar, ~50 guests | 2x3 m | Can't be shrunk without slowing service |
| Bar, larger events | 3x4 m | Build it in from the start |
| Entrance | 3 m internal clearance | Needed for flow and safety |
| Aisles | 1.2 m wide minimum | Adds 15 to 25 sq m overall |
| Guy ropes (traditional) | 1 m clearance each side | Clearspan marquees avoid this entirely |
When you measure your space, remember a traditional marquee needs a full metre of clearance on every side for the guy ropes. We've turned up to sites where the lawn looked big enough on paper and wasn't, once the ropes were accounted for. If your space is tight, a clearspan marquee is self-supporting and needs none of that extra room, which is often what makes a smaller garden work.
When it's worth sizing up
Round up whenever your guest numbers fall between two marquee capacities. When space is borderline, going one size larger usually costs somewhere between £200 and £600, and it buys you a layout that works instead of one that's fighting for room. That's money well spent every time.
Two more things we'd always factor in. Multi-zone layouts, where you've got separate areas for dining, a bar and dancing, need 30-40% more space than a single open-plan setup. And in the UK, you plan for rain even in July. So we size for everyone comfortably indoors.
Still not sure what size marquee you need? We'll work it out with you.
You can get a long way with the tables above. But a plan on paper can't see your access, your ground, or the guy rope clearance your garden does or doesn't have.
Every Ruby's Marquees installation starts with a free site visit. We come to your location, measure the space properly, and recommend the right size for your event and your guest count.
