What this calculator does
Seating capacity comes from table edge rather than table area. A round table seats by its circumference at about 70 cm per guest, so a 170 cm round table seats 7. A rectangular table seats along both long sides at about 60 cm per guest.
The round table result is not smooth, which surprises people. Going from a 150 cm to a 170 cm table adds only one seat, and then 180 cm adds another. Because seats must be whole numbers, a modest increase in diameter sometimes buys nothing at all and sometimes buys a full extra place.
The formula
For a round table the seats are the circumference, π times the diameter, divided by 70 cm and rounded down. For a rectangular table the seats are the length divided by 60 cm, rounded down, doubled for both sides. Tables needed is the guest count divided by seats per table, rounded up, so the last table is usually not full.
| Term | Meaning |
|---|---|
| 70 cm per guest | The round-table edge allowance, which gives comfortable elbow room. |
| 60 cm per guest | The rectangular-table allowance per side. |
| Spare seats | The difference between total seats provided and guests, since tables come in whole numbers. |
| Head of table | Additional seats at the ends of a rectangular table, not counted in this calculation. |
The inputs explained
| Field | What to enter |
|---|---|
| Guests | Number of guests to seat. |
| Table shape | Round or rectangular, which changes how seats are counted entirely. |
| Diameter (round) or length (rectangular) (cm) | Diameter for a round table, or length for a rectangular one, in centimetres. |
When to use it
Planning a wedding or function
Table hire is priced per table, so the count is the figure that determines the cost as well as the floor plan.
Choosing table size
Larger round tables seat more but take considerably more floor space, and the seats-per-table figure shows what the extra diameter actually buys.
Comparing round against rectangular
The two seat very differently for the same nominal size, and comparing them directly is the point of the shape selector.
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 many tables does 120 guests need?
A fixed guest count across a range of round table diameters.
| Table diameter | Tables needed | Seats per table | Total seats provided | Spare seats |
|---|---|---|---|---|
| 150 cm | 20 | 6 | 120 | 0 |
| 170 cm | 18 | 7 | 126 | 6 |
| 180 cm | 15 | 8 | 120 | 0 |
Questions
How many people fit at a round table?
About one per 70 cm of circumference. A 150 cm table seats 6, a 170 cm seats 7 and a 180 cm seats 8. Squeezing more in is possible but uncomfortable, particularly once place settings and glassware are laid.
Should I use round or rectangular tables?
Round tables suit conversation, since everyone can see everyone. Rectangular tables fit more people into a narrow room and are easier to arrange in rows. For the same floor area, rectangular generally seats more.
Do the ends of a rectangular table count?
Not in this calculation, which counts only the long sides. Adding a seat at each end is common and adds two per table, though it can crowd the corners of the place settings on either side.
How much floor space do I need per table?
Allow roughly 150 cm around each table for chairs and for people to walk behind them. A 180 cm round table therefore occupies close to a 480 cm square of floor once access is included, which is considerably more than the table footprint.
For tablecloth sizing to match those tables, see the tablecloth size calculator. For decoration, see the balloon arch calculator.