ezPlatter The most common catering mistake is not the format or the menu. It is guessing at quantity. Order too little and people leave hungry, and someone has to make an awkward second call to the restaurant. Order too much and you are paying for trays that go straight into the office fridge or the trash. The good news is that food quantity is one of the few parts of catering that comes down to simple math once you know the baseline numbers.
Start with the baseline: about a pound per person
For a standard buffet, plan on half a pound to a full pound of food per person, not counting dessert or drinks. That splits roughly into 4 to 6 ounces of protein, 4 ounces per side dish, and a cup of salad if you are serving one. A boxed lunch already builds this in, since each box is one full meal, so the math there is simpler: one box per confirmed attendee, plus a small buffer for anyone who forgot to RSVP.
If you are ordering breakfast instead of lunch, the numbers shift a little. Plan on 2 eggs per person or one 3-egg omelet, 2 to 3 slices of bacon or sausage links, and 1 to 2 pancakes or pieces of french toast if that is on the menu. Breakfast portions run a bit smaller overall than lunch or dinner, so you can lean toward the lower end of the pound-per-person range for a morning event.
Adjust for how long the event actually runs
A 45-minute lunch and a 3-hour open house need different quantities even with the exact same headcount. If people are going to be in the room for hours, especially with grazing-style food or an open snack table, add 15 to 20 percent more food than the baseline. For a quick sit-down lunch where people eat once and then leave, the baseline amount is enough on its own. Time of day matters too: a dinner-hour event tends to draw bigger appetites than a mid-morning meeting, so shift toward the higher end of your range for evening events.
Buffet vs boxed vs appetizers: different math for each
- Buffet: add a 10 to 15 percent buffer over the raw per-person math. Self-serve portions are uneven in practice, and the first few people through the line tend to take more than the people at the back.
- Boxed lunches: no real buffer needed beyond a couple of spares for late RSVPs or walk-ins, since each box is a fixed, pre-portioned amount. This is the easiest format to get exactly right.
- Appetizer or cocktail-style events: plan on 6 to 8 pieces per person per hour, spread across 3 to 4 different items so nothing runs out first while something else sits untouched.
A worked example: planning for 35 people
Say you are ordering a 2-hour buffet lunch for 35 confirmed attendees. Start with the baseline: 35 people at roughly 0.75 pounds each comes to about 26 pounds of food. Since it is a buffet, add a 12 percent buffer, which brings you to roughly 29 pounds. Because the event runs 2 hours rather than a quick 45-minute lunch, add another 10 percent for the longer window, landing around 32 pounds total. That final number, not the raw 26-pound baseline, is what you should actually order.
For drinks at that same event, plan on 1 to 2 non-alcoholic drinks per person for the first hour, then 1 drink per person for each additional hour. For 35 people over 2 hours, that works out to roughly 70 to 105 drinks total, which usually means a mix of canned or bottled drinks plus a drink dispenser if the restaurant offers one.
A quick reference for common group sizes
For 20 people, that is roughly 15 to 20 pounds of food total for a buffet, or 20 boxed lunches with one or two spares. For 50 people, figure 35 to 50 pounds for a buffet, or 52 boxes. For 100 people, most caterers plan for 75 to 100 pounds depending on how heavy the menu is, and round boxed lunch orders up to 105 to cover stragglers and last-minute additions.
When in doubt, round toward the box format
If you are not confident in your headcount, boxed or individually packaged options are more forgiving than a buffet. A buffet tray that runs short is obvious and awkward in the moment, since everyone can see the empty tray. A few extra boxed lunches just become next-day leftovers, which is a much smaller problem to have. For more on this, see our guide on avoiding running out of food entirely.
Common mistakes to avoid
- Ordering against the invite list instead of confirmed attendance. A meeting with 40 invitations rarely seats 40 people.
- Forgetting drinks and dessert in the per-person math, then realizing at the last minute that neither was actually ordered.
- Choosing a buffet for an event with an unpredictable schedule, where food sits out losing quality while people trickle in late.
- Not accounting for vegetarian or vegan guests, then running out of the one dish that covers them.
Quick answers
Do I need to feed the vendors or staff working the event? Yes, if anyone is on-site setting up, serving, or running AV for several hours, count them in your headcount rather than assuming they brought their own food.
What if my headcount changes the day before? Most restaurants can adjust an order slightly with 24 hours notice. Call and ask rather than assuming the original order will just stretch to cover extra people.
Step by step: turning a headcount into an actual order
Start by writing down your confirmed headcount, not the invite list. Next, decide your service style (buffet, boxed, or grazing), since that determines which buffer percentage applies. Multiply your headcount by the per-person weight or piece count for that style, then apply the buffer. Finally, round up to whatever tray or box sizes the restaurant actually sells, since most catering menus come in fixed increments like trays that serve 10 or 20 rather than an exact number.
A second worked example: a smaller group of 12
For a small team lunch of 12 people, the numbers work the same way but the buffer matters less in absolute terms. At 0.75 pounds per person, the raw total is 9 pounds. With a 10 percent buffer for a buffet, that becomes about 10 pounds, which is a small enough difference that it usually just means picking the next tray size up rather than doing precise math. For groups this size, boxed lunches are often simpler anyway: order 12 boxes plus 1 spare, and the sizing question mostly solves itself.
How restaurant tray sizes usually work
Most fast food catering menus sell trays in set sizes, often labeled as serving 8 to 10, 15 to 20, or 25 to 30 people. When your calculated total falls between two tray sizes, round up rather than down, or let our catering calculator work out the right size for you, and consider mixing tray sizes rather than always jumping to the next largest one. For example, a group of 28 might be better served by one tray for 20 plus one small tray for 10, rather than a single oversized tray meant for 30.