Event Planning Guide: How to Estimate Quantity for Your Party

Quantity. The question “how many?” plagues every event planner sooner or later. Getting an appropriate quantity of, well, everything, is critical to running a successful party.

After all, if you have too little of something – whether it’s napkins, prizes for a carnival game, or seats in a dining area – it leaves people feeling left out, ignored, or unsatisfied. Conversely, if you have too much of something – like food, games, or entertainers – you’re going to have a party looking sparse and unattended. Worse, for consumables in particular, you end up causing excess waste, and the expense of hiring or buying stuff you didn’t need.

Every quantity you need to specify for your party depends on one all-important number: the number of attendees. So how do you estimate the number of people who will attend your party?

Different Ways to Estimate Attendance

There are a few different ways you can estimate attendance.

The first and the easiest is to simply do a headcount of the people who are invited. For a child’s birthday party, for example, you can do a count of her friends, or all of her classmates in general, and extend a broad invitation.

Of course, this doesn’t work too well in practice. We’ve all read the sad stories of a child who invited dozens of friends, only for no one to show up on the day of the party. The same goes for doing a headcount of the office for a retirement party; many of your coworkers aren’t going to show up for one reason or another.

One of the most common methods is to set up an RSVP system. RSVP is an acronym in French, for “repondex s’il vous plait”, or “please respond.” We all know it as that letter we get before a wedding or other party where the planners involved want a headcount they can use to estimate attendance.

Weddings make heavy use of the RSVP in particular because the cost of planning depends heavily on the headcount, so until a rather close headcount is obtained, other planning cannot proceed.

An RSVP isn’t perfect. Some people will plan to attend a party but will get sick, have a family emergency, or have another reason crop up to not attend at the last minute. Others might RSVP but simply change their minds. Some people will always drop out. Common wisdom is that you can expect about 10% of RSVPs will end up not attending the party by the end. Still, that’s a pretty close estimate.

Another consideration is children. You might get 100 people planning to attend via RSVP, but how many of those people have children they plan to bring, who they don’t mention in the RSVP form? Children need food, snacks, entertainment, and other considerations that should be planned.

If the children are the core of the party, such as a child’s birthday party, that’s one thing. If they’re incidental, they can be easy to forget. Many party planners end up letting the parents handle entertaining and feeding their kids, but sometimes it can pay off to have a small child’s area or child’s menu options available.

A third way of estimating party attendance is to simply limit party attendance entirely. When planning and announcing your party, tell invitees that you only have 100 seats available, first-come, first-served. A registration form allows you to keep track of how many seats you still have available. The limited quantity means you have a hard cap on the number of resources you need to plan for.

An attendance cap solves half of the problem of estimated attendance. You’ll never go over, and thus you’ll never end up with less entertainment or less food than is required for your party. Unfortunately, it doesn’t do anything to solve the unannounced drops problem. There will always be people who can’t make it, so there will always be surplus in your supplies.

Once you have your general headcount, then you can start making estimates for how much food, drink, space, entertainment, and other details you’ll need.

Estimating Food and Drink

Food is generally the heart and soul of a great party. Whether it’s finely catered gourmet entrees or finger foods from a food truck, once you know how many people are going to be in attendance – give or take a few – you can start estimating the amount of food to prepare.

First, you need to figure out what kind of food you’re providing. Are you catering a full dinner, appetizers, and desserts? Are you simply providing snacks for a party that runs throughout the day, and letting your guests plan their meals themselves?

General recommendations look something like this:

• Around 6 appetizers per person per hour. A single appetizer here can be defined as a small snack: no one is going to eat six trays of mozzarella sticks in an hour.
• Around 1-2 sandwiches per person. Sandwiches are often essentially meals, so this works as your main course if you aren’t otherwise providing dinner.
• Around 3 appetizers per person per hour if you’re providing dinner as well. Dinner, of course, is one per person, though it gets more complicated if you want to provide multiple options.

You can also look for more specific statistics about individual food items. For example, with a bulk salad, four heads of lettuce typically handle five people. Four ounces of pasta is a decent portion for one person. One 18 lb. turkey can feed 25-30 people. Miniature desserts, like small brownies or cupcakes, tend to go three per person.

You can include a poll about food in an RSVP card if you wish. This is, again, a common technique for wedding planning. Maybe you’re planning to provide three different dinner options; ask attendees to reply with the dinner choice they would prefer, and you can have a relatively accurate count for how many of each you need. Of course, stock a few extra to make sure you have enough for each person who wants one, and for a couple who change their minds.

You can’t have food without drinks, right? Here, you have one critical choice to make: do you have a bar?

Providing alcohol can be a great idea to liven up some parties and provide a certain level of social lubrication. It’s also only appropriate for certain kinds of parties. Parties where minors will be in attendance make it trickier to manage, and it’s certainly not appropriate for a child’s birthday.

Keep in mind that, depending on where you live and where you plan to host your party, you may have regulations on whether or not you can have alcohol. There are, of course, federal laws regulating alcohol. There are state laws, which you should be familiar with. Then you’re likely to have local-level laws or regulations, regarding things like public consumption or public intoxication. You may also have venue-specific rules, as many venues don’t want the potential for alcohol-fueled destruction.

You can estimate alcohol consumption using guidelines like:

• The average alcohol drinker typically will consume two drinks in their first hour, and one drink per hour afterwards.
• The spread of consumption typically ranges around 30% beer, 30% wine, and 40% liquor, though this will vary by tastes and attendance demographics.

You may also need to factor in the labor of a bartender and someone to card anyone who wants to partake in the booze. It’s typically easier to hire a bartender to cater your bar than it is to manage everything yourself, though some more casual parties can just throw a bunch of six-packs and bottles on a counter and trust guests to be reasonable with them.

Similar numbers can apply to soft drinks as well. Sodas can go one bottle per person per hour, as can other beverages in normal 20-oz. or so bottles. The exception is water; you should try to provide as much water as possible, especially if it’s free for guests.

Don’t forget you also need to provide enough tableware to suit the food and drink you’re providing. Plates, cutlery, glasses, all of the assorted bartending and catering equipment; it’s all important. Make sure you have enough of everything you need. At least it’s easy enough to buy excess paper plates and plastic cutlery if need be.

Estimating Space

Which came first; the size of the venue or the size of the party?

Sometimes, when you’re planning a party, you pick the venue and go from there. This often happens when you have a venue lined up before the party is planned, or when you’re operating on a strict enough budget that a venue needs to be chosen before other planning can begin.

These are cases where it might be worthwhile to restrict the number of possible attendees. Over-crowded parties are rarely pleasant – they’re a specific kind of subculture and aren’t planned in quite the same way – and there are often occupancy limits to venues. Occupancy limits are about more than just space; they’re about health and safety.

You will also want to consider the amount of space for each person to occupy at any given time. If your venue is something like a park or outdoor entertainment grounds, you have plenty of space for people to wander and form their own pods. In an enclosed venue, however, you might need to consider square footage.

• If there will be physical activities, dancing, or if the attendees are strangers or acquaintances, allow for 10 square feet per person.
• If the attendees are a mixture of friends, strangers, and potential enemies, you can pack them a little tighter, but still allow 7-8 square feet of space per person.
• If your guests are all friends – like a family gathering, baby shower, or friend-based celebration like friendsgiving – you can crunch people in around 5-6 square feet per person.

With space comes other considerations. Seating, for example, becomes important for any lengthy party. You need one chair per person for however, many people will be attending at any given time. Even if not everyone is sitting at once, people tend to “claim” a seat and leave their stuff on it, so even if there are dozens of seats with no one in them, there may be no seats available for people who want one.

There’s also a psychological trick you can pull if you want to get people closer together and socializing. Initially, only provide around 85-90% of the chairs your party needs. People will sit nearer one another to utilize available chairs, and can get to talking when they need to borrow one. Then, once that’s established, you can bring out the rest of the chairs, much to the relief of the rest of the party.

Rounding Up

When all is said and done, estimates for attendance, space, food, and everything else are all just that: estimates. A big part of successful event planning is learning how to estimate these factors in a way that is relatively accurate and keeps the party moving forward without issue.

This is one reason why it can be a worthwhile option to simply hire an event planner to calculate everything for you. Do you have time to learn all the statistics, to think of everything from tableware to food to prizes for games, and do all the calculations yourself? Or would it be more worth your while to hire a professional? That’s up to you.