The two numbers everything else follows
- How many people, as a range you are willing to defend in a conversation with both families.
- What the whole thing can cost without borrowing, written as one figure.
- Every other decision is downstream of those two, and made afterwards.
The order that works
- Guests first: one list, split into must invite, would like to invite, and if there is room.
- Money second: a single total, agreed and written down by whoever is paying.
- Venue third: capacity decides what the guest list can be, and the date decides everything else.
- Food and drink fourth: usually the largest variable and the easiest one to scale per head.
- Photography and music fifth: book early, because the good ones go early, and their price moves less with the head count.
- Clothes, flowers and stationery last: the lines where the total is easiest to change honestly.
Where the numbers quietly break
The break is rarely one large mistake. It is a hundred small additions made after the figure was agreed, each of which sounded small at the time, none of which was written down.
Write every addition into the file on the day it appears, with its cost, and read the running total once a week. A number you can see changes the next decision; a number you are carrying around in your head does not.
- Deposits are real money. Count them on the day they are paid, not when the balance falls due.
- Vendor quotes often exclude tax and service. Add both before comparing two quotes.
- Keep two columns: what you expected and what you agreed. The gap between them is the useful part.
The last month
- Freeze the guest list, and accept that it will move once more anyway.
- Confirm every supplier in writing, with times and addresses, in one document.
- Print the day plan twice and give it to two different people who will not be standing together.
- Stop adding. The last month is for confirming, not for improving.
The free tool for this
There is no calculator that answers this one honestly, so here is the free set: eight calculators for rates, quotes, invoices, splits, prices and fees. They run in the page and send nothing anywhere.
If you would rather not build it yourself
Event Plan is the unglamorous spine of the day: one guest list everyone updates, seating that checks itself against table capacity, and a budget that shows quotes beside the plan. Event Plan is $14. See it on the shop, and there is a plain page about it here: what it holds.
Questions people actually ask
Should we set the date first?
Date and venue are one decision, and both come after the guest range. Each constrains the other, so choosing either alone usually means choosing again later.
How do we handle two families paying?
One total, one person holding the file, and a written note about which side covers which lines. Most of those arguments are about the file rather than the money.
Read next
How to plan an event guest list and seating without chaos, The event planning timeline: what to settle when.