Seating Rules Solver
Dividing guests by seats tells you how many tables to hire. It cannot tell you that the rule you wrote in March and the rule you wrote in June cannot both be true. Enter who must sit together and who must be kept apart, and get a plan — or the reason there isn’t one.
Sitting together passes along a chain
Seating people together is not a preference you apply pair by pair; it is a relation that spreads. Put Ann with Ben, and Ben with Cara, and Ann is sitting with Cara — nobody decided that, but the table did. Keep going and the rules quietly fuse guests into groups that must share a table, and those groups are what your plan is really made of. Two consequences follow, and both bite late.
The first is that a keep-apart rule between two people in the same group cannot be satisfied at any number of tables. Seating software will usually take both rules and then silently break one, so you find out when a guest arrives and reads the place card. The second is that keeping people apart costs tables: three guests who must all be separated occupy three tables between them however large the tables are, so the arithmetic of guests ÷ seats quietly understates what you need to hire.
Once the plan holds, work out what the evening costs with the Event Budget Calculator, and settle the dress line on the invitation with the Dress Code Analyzer.
Frequently Asked Questions
Why can't I keep these two guests apart?
Almost always because a chain of 'must sit together' rules has already put them at one table. Seat Ann with Ben because they are married, and Ben with Cara because they travelled together, and you have seated Ann with Cara without ever deciding to. Sitting together is transitive — it passes along the chain — so a later rule keeping Ann and Cara apart is not merely awkward, it is impossible, and adding tables will never fix it. This tool finds that before you print place cards, and names every link in the chain so you can see which rule to release.
How many tables do I need?
More than the division suggests, if you have people to keep apart. Dividing guests by seats assumes anyone may sit anywhere; three guests who must each be kept apart from the other two need three tables between them no matter how much room each table has. The plain calculation cannot see that, because it never learns the rules. This one reports the count the rules actually force, and how many tables beyond the arithmetic that came to.
What counts as a 'must sit apart' rule?
Fewer pairs than you would think, and that is the point. Every keep-apart rule you add makes the plan harder and can quietly cost you a table, so it is worth reserving them for the pairs where sharing a table would genuinely spoil the evening — a bitter divorce, a business fallout, a feud everyone knows about. Mild awkwardness is better solved by which end of a long table someone sits at, which is a judgement no solver should be making for you.
Does it decide who gets the best table?
No, deliberately. It satisfies the constraints you set and stops there: it has no view on whether the table by the kitchen door is a demotion, who should face the band, or which aunt counts the distance to the top table. Those are the parts of seating that are actually about people, and they are yours to settle. What this removes is the mechanical part — the part where you discover at eleven at night that two rules you wrote a month apart cannot both be true.
Is the arrangement it gives me the only one?
No. Most guest lists admit many valid arrangements, and this returns one that satisfies every rule rather than searching for a best one — there is no agreed definition of 'best' that a program could optimise. Treat it as a working draft that is guaranteed not to break any rule you set, then move people between tables freely as long as you keep the groups intact and the kept-apart pairs separated.
Satisfies the rules you enter; it does not rank guests, optimise seating or judge who sits where. A working draft for planning, not a substitute for knowing your own family.