How to use it
Put each party on its own line: a couple, a family, a group of friends. Separate their names with commas. Everyone on one line sits at the same table. Add the top table separately if you’re having one.
Set how many tables you have and how many seats at each. The plan builds as you type. Add a title, such as your names and the date, and print it on A4. At the foot is a line that should measure 50 mm, so you can check it printed at full size.

How it is worked out
The method is ours, and simple. The biggest parties go first, each to the first table with enough empty seats. Then the smaller ones fill the gaps. A party too big for one table is split over the fewest tables, and the tool tells you. Anyone who doesn’t fit is listed by name, so nobody goes missing. It also tells you how many tables of that size you need for everyone.
It is a first draft. Move people around once you see it: who gets on, who has small children, who needs to sit near the door. Then print the final version.
Planning the rest? Try the order of the day and the planning checklist.