How to budget for an event
An event budget is not a single number, it is a living document of estimated versus actual, tracked line by line from the first quote to the final invoice. Most budget overruns are not caused by one big mistake, they come from a handful of small costs that quietly compound: a service charge nobody priced in, a headcount that crept up after catering was locked, an AV overtime fee at 11pm. Without a working budget you find out about all of that at once, after the event, when it's too late to change anything. This guide is for anyone building a budget for the first time or the tenth: how to structure it, what to hold in reserve, and the costs that catch first-time planners out every time.
The Event70 Team · 3 min read
- 1
Start from the goal, not the wishlist
Decide what the event actually has to achieve, closing sales, launching a product, thanking a team, and what you are realistically willing to spend to achieve it. That top-line number is your ceiling, set before you start collecting vendor quotes, not after. Every line item then competes for room under that ceiling, which forces real tradeoffs early: a bigger venue might mean a smaller catering spend, not both.
- 2
List every category, then every line
Group costs into broad categories: venue, catering, AV and production, talent, marketing, staffing and contingency. Then break each category into specific, quotable line items rather than one lump figure, so 'AV' becomes sound, lighting, screens, technician labor and cabling as separate rows. Specific line items are what let you get accurate vendor quotes and spot exactly where a category is running over, instead of one vague number that hides the problem.
- 3
Estimate high, then replace with quotes
Start with conservative, slightly pessimistic estimates for every line, then swap each one for a real vendor quote as you book it. Keep estimated and actual in side-by-side columns rather than overwriting the estimate, so you can always see your total exposure: what you originally planned to spend, what you've now committed to, and the gap still open. That gap is your real remaining flexibility.
- 4
Hold 10 to 15 percent for contingency
Something always comes up: AV overtime because a session ran long, extra chairs because RSVPs beat your estimate, a last-minute rental to fix something the venue walkthrough missed. Hold 10 to 15 percent of your total budget as a dedicated contingency line, untouched until something genuinely unplanned needs it. Without that buffer, one surprise gets absorbed by cutting a line that mattered, or by simply overspending.
- 5
Watch the costs that hide
Service charges and gratuity on catering (often 20 to 25 percent on top of the food total), AV labor and overtime once a session runs past the contracted hours, delivery and rental fees that show up as separate line items from the rental itself, sales tax, and per-person costs like meals or gift bags that scale automatically as your headcount rises. This is where budgets quietly overrun, in the fees around the number, not the number itself.
- 6
Track paid versus owed
Mark each line as estimated, committed (a signed contract or confirmed order) or paid. A budget that only shows totals hides the fact that half your committed spend hasn't actually left your account yet. Knowing what's already out the door versus what's still owed is what tells you whether you're genuinely on track, or just haven't been billed for the overrun yet.
- 7
Reconcile after the event
Fill in final actuals for every line, including the ones that came in as a single combined invoice you have to split back out, and compare each to your original estimate. Note which categories you consistently underestimate, catering service charges and AV overtime are common repeat offenders, and adjust next time. That reconciled record is the fastest way to make your next event's budget accurate on the first pass instead of the third.
See it in Event70
RSVPs
- JAJordan Avery+2confirmed
- SPSam Patel+1confirmed
- RCRobin Cho+1pending
- DNDevi Nair0declined
Event70 turns this into a working plan: a live run of show, an assignable checklist, RSVPs, a budget and the day-of, all on one event.
Frequently asked questions
How much contingency should I include in an event budget?
Ten to fifteen percent of your total budget is a reasonable starting point for most events, held as its own untouched line rather than folded into other categories. Larger or first-time events, or ones with a lot of moving vendor pieces, lean toward the higher end. A contingency line only works if it's genuinely protected from being spent early on something that felt urgent at the time.
What are the most commonly underestimated costs in an event budget?
Catering service charges and gratuity, which often add 20 to 25 percent on top of the food and beverage total, AV labor once a session runs into overtime, and delivery or rental fees charged separately from the rental itself. Sales tax on the full invoice is another one people forget to line-item. These are rarely huge individually, but together they're where a tight budget goes over.
Should I set the budget before or after choosing a venue?
Set your top-line budget and your goal before you shop for a venue, not after. Otherwise you end up anchoring to whatever the first venue you liked costs, rather than what the event can actually afford. Once you have a ceiling, you can evaluate venues against it directly, including whether their catering minimums and service fees fit inside what you have left for everything else.
How do I budget for an event when I don't know the final headcount yet?
Budget against a realistic range, not a single guess: a conservative low number for anything with a fixed cost regardless of turnout, like AV or staffing, and your expected or slightly optimistic number for anything that scales per person, like catering. Most caterers and venues let you adjust the guaranteed headcount up to five to seven days out, so build your budget around that deadline, not the invite date.
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