What this calculator does
Tent size comes from the guest count multiplied by an area per person, and that area depends entirely on the seating style. Eighty guests need 560 square feet theatre style and 960 square feet for a formal dinner, nearly double for the same people.
The figure covers seated or standing guests only. A bar, a buffet, a dance floor, a stage or a cake table all need their own space on top, and it is common to need a third again beyond the seating area once those are added. Working out the seating first and listing the extras separately is more reliable than one combined guess.
The formula
The guest count is multiplied by the square feet per person for the chosen style. The suggested footprint divides that area by a standard tent width and rounds the length up to the next multiple of the width, since tents are made in fixed sections. Theatre seating is tightest at 7 square feet per person and formal dinner seating loosest at 12.
| Term | Meaning |
|---|---|
| Theatre seating | Rows of chairs facing one way, about 7 ft² per person. |
| Conference seating | Rows with tables, about 8 ft² per person. |
| Formal dinner | Round tables with chairs and service access, about 12 ft² per person. |
| Footprint | The tent outside dimensions, made up of fixed-width sections. |
The inputs explained
| Field | What to enter |
|---|---|
| Guests | Number of guests. |
| Seating style | Seating style, which sets the area per person. This changes the answer more than anything else. |
| Standard tent width (ft) | Standard tent width in feet. Hire companies stock fixed widths, commonly 20, 30 or 40 ft, and extend by adding length. |
When to use it
Hiring a marquee
Hire companies quote by footprint, and the area calculation identifies which of their stock sizes will do.
Comparing seating layouts
A formal dinner needs close to double the space of theatre seating, which can decide the layout before the tent is booked.
Checking a site fits
The footprint has to fit the ground available with room for guy ropes and access, which the area alone does not tell you.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How much space does each seating style need?
The same guest count across three seating styles.
| Seating style | Floor area needed | Suggested footprint | Area per guest used |
|---|---|---|---|
| Theatre | 560 ft² | 20 ft × 30 ft | 7 ft² |
| Casual mixed | 800 ft² | 20 ft × 40 ft | 10 ft² |
| Formal dinner | 960 ft² | 20 ft × 50 ft | 12 ft² |
Questions
How big a tent do I need for 80 guests?
Between 560 and 960 square feet depending on layout: about 560 for theatre seating, 640 for conference seating and 960 for a formal dinner. Add separately for a bar, buffet, dance floor or stage, which can easily add a third again.
How much space does a dance floor need?
A common planning figure is 4 to 5 square feet per person, assuming roughly a third to a half of guests dance at once. For 80 guests that is around 150 to 200 square feet, which is additional to the seating area calculated here.
Does the tent width matter?
Yes, because tents are built from fixed-width frames extended in sections along their length. A given area can be a long narrow tent or a short wide one, and the shape affects both sightlines and whether it fits the site. Ask what widths your supplier stocks.
Should I allow extra for bad weather?
Yes. In poor weather guests who would have spilled outside stay inside, so a tent sized for good conditions feels cramped. If the event depends on outdoor overflow, size the tent as though that overflow will not happen.
For seating arrangements inside, see the event seating calculator. For table linen, see the tablecloth size calculator.