The guests have been invited and the RSVP’s have returned. Now that your food truck catering client has a final head count and knows how many guests to expect, how do you know how much food to buy or order to satisfy their needs? This is a common question and is worthy of some consideration. No caterer ever wants to be in the embarrassing situation of having run out of food. Neither is it good to over-order, over-pay, and have to dispose of any leftovers.

Catering Formula

Here’s the exact formula I use to determine the cost of a catering event. Don’t worry, you don’t need to a math whizz to use this same approach.

Let me break down each of these variables:

  1. Food Cost (FC): The total cost of ingredients needed to prepare the menu.
  2. Labor Cost (LC): Wages paid to staff for the event, including prep, service, and cleanup time.
  3. Rentals (R): Cost of renting equipment or additional items not typically found in the food truck, such as tables, chairs, linens, etc.
  4. Transportation (T): Cost of transporting the food truck and any additional supplies to and from the event location.
  5. Miscellaneous (M): Any other costs associated with the event, including permits, insurance, or decor.
  6. Profit Margin (PM): The percentage of the total cost you add on top to ensure profitability. This is typically between 10% to 30% or more, depending on your business goals.

Example Calculation:

  • Food Cost (FC): $500
  • Labor Cost (LC): $300
  • Rentals (R): $100
  • Transportation (T): $50
  • Miscellaneous (M): $50
  • Profit Margin (PM): 20% or 0.20

Applying the formula:

($500 FC +300 LC +100 R +50 T +50 M) × (1+0.20) = $1,200 Total Event Cost

This formula gives you a baseline cost for the event. You would quote the client at least $1200 to cover your costs and include your desired profit margin. Depending on your specific situation, you may need to adjust or add more components to accurately reflect the cost of catering an event. Don’t forget to add spot for a tip too!

Calculating How Much Food To Buy

As an experienced food truck owner, I’ve learned that calculating food quantities for catering events goes beyond just knowing the headcount and event duration. Here’s a deeper insight into managing your costs and ensuring customer satisfaction, Here are the steps and considerations I take to make the calculation as accurate as possible.

1. Understand the Event Details

  • Number of Guests: The most crucial piece of information. Always plan for a few extra people than the number you’re given, as it’s common for unexpected guests to show up.
  • Determine Type of Event: Weddings, corporate events, and casual parties have different food consumption patterns.
  • Time of Day: Breakfast, lunch, and dinner events require different quantities and types of food. People tend to eat more at dinner than at lunch or breakfast.
  • Event Duration: Longer events require more food and drinks as people will consume multiple times.
  • Guest Demographics: Consider the age and gender mix of your guests. Younger crowds and predominantly male gatherings might eat more, for instance.

2. Decide on the Menu

  • Variety and Balance: A mix of protein, vegetables, carbs, and dessert. Remember to include options for vegetarians, vegans, and those with common dietary restrictions like gluten-free.
  • Popular Items: Increase quantities for crowd-pleasers and signature dishes.
  • Portion Size: For buffet style, plan on larger portions per person. For a tasting menu, smaller, bite-sized portions are appropriate.

3. Calculate Quantities

  • Per Person Basis: Start with standard catering industry averages (e.g., 4-6 oz of protein, 3-5 oz of vegetables, 4-6 oz of carbohydrates per person for a meal).
  • Adjust for Event Type: Increase quantities for all-day events, decrease for cocktail parties.
  • Beverages: Plan on 2-3 drinks per person for the first hour and 1-2 drinks per person for each additional hour.

4. Consider Logistics

  • Storage and Transportation: Ensure you have the capacity to store and transport the food safely.
  • Equipment and Serving Ware: Make sure you have enough equipment to keep food at the right temperature and the correct serving ware for the menu you plan to serve.

5. Factor in Waste and Extras

  • Overage: Plan for an overage of 5-10% to accommodate unexpected guests or consumption patterns.
  • Leftovers: Have a plan for leftovers, whether it’s donating to a local shelter or providing take-home containers for guests.

6. Use Past Experience

  • Record Keeping: Keep detailed records of past events, including what you served, how much was consumed, and any feedback from guests. Use this data to inform future planning.

7. Consult with the Client

  • Preferences and Budget: Discuss the client’s preferences and budget in detail to ensure their expectations are met while staying within their budget.

8. Conduct a Final Review

A few days before the event, review your calculations based on the final RSVP count and adjust as necessary. By meticulously following these steps and leveraging past experiences, food truck owners can accurately calculate how much food to buy for catering events, ensuring guests leave satisfied and the business operates efficiently without excessive waste.

Develop a Catering Checklist

Shindigs Catering

The catering truck outside a wedding event.

This checklist can be modified as needed to fit the specific requirements of different events or to align with the unique offerings of your food truck. This happens to be the checklist I used in my own food truck business. You can copy and paste this into you own spreadsheet and use.

[ ] Confirm Number of Guests[ ] Determine Type of Event (Wedding, Corporate, Casual, etc.)[ ] Establish Time of Day (Breakfast, Lunch, Dinner)[ ] Calculate Event Duration[ ] Assess Guest Demographics (Age, Gender, Dietary Restrictions)[ ] Finalize Menu Selection[ ] Protein Dishes[ ] Vegetable Dishes[ ] Carbohydrates[ ] Desserts[ ] Vegetarian/Vegan Options[ ] Special Dietary Requirements (Gluten-Free, Allergies)[ ] Adjust Quantities for Popular Items[ ] Decide Portion Sizes (Buffet Style, Bite-Sized for Tastings)[ ] Calculate Food Quantities[ ] Protein (4-6 oz per person)[ ] Vegetables (3-5 oz per person)[ ] Carbohydrates (4-6 oz per person)[ ] Adjust for Event Type and Duration[ ] Plan Beverage Quantities[ ] 2-3 Drinks Per Person for First Hour[ ] 1-2 Drinks Per Person for Each Additional Hour[ ] Check Storage and Transportation Capacity[ ] Ensure Adequate Equipment and Serving Ware[ ] Plan for 5-10% Overage for Unexpected Guests/Consumption[ ] Develop Plan for Leftovers[ ] Review Records from Past Events for Insights[ ] Discuss and Confirm Client Preferences and Budget[ ] Conduct Final RSVP Count Review and Adjust Plans Accordingly

Incorporating these insights into your planning process will not only help in accurately calculating food quantities but also in managing your costs effectively, reducing waste, and leaving a lasting impression on your clients.

My Rule of Thumb Catering Events  

Here’s my rule of thumb for catering events after more than a half a decade of experience.


  • If you’re working an evening function with no dinner, plan on at least 10 – 15 pieces per person. Round up, especially if it’s going to be served buffet style, as people tend to eat more than if a tray is passed.
  • If you’re serving pre-dinner appetizers, plan on 3 – 5 pieces per person, and choose lighter food options, as dinner will follow.
  • If you’re catering a mid-day function with a meal following, offer 1 – 3 pieces per person.
  • Beverages: Plan on about 3 beverages per person, with coffee drinkers consuming on average one cup every 1 – 3 hours.


  • People usually drink 2 beverages on average – either juice, coffee, tea, etc.
  • Plan on a main entree per person, along with two sides, including bread. Fruit makes an excellent breakfast dessert. Estimate about 3 – 5 pieces of cut fruit per person, or one cup or less of fruit salad.
  • If you’re serving pastries only, plan on 2 pieces per person.


  • For hors d’oeuvres, plan on 2 – 4 per person.
  • Offer a main entree with 2 – 3 sides, including a starch and a dessert.
  • Offer a selection of drinks, including pop, beer, lemon water, etc.
  • If you’re having sandwiches, allow for 1 -2 per person.


  • Have 3 – 5 hors d’oeuvres per person, depending on the number of courses.
  • Plan on a main entree and 2 – 3 sides, either veggies, beans, pasta, etc.
  • Offer small portions of bread, salad, or soup.
  • Always have water, along with other beverages.


  • Plan on 1 – 3 servings per person.
  • Offer one slice of cake, tart or pastry, or 4 oz. of a creamy dessert, i.e. mousse. If you have a large variety, serve smaller portions.
  • Coffee consumption peeks after dessert is served.

Lessons Learned

It was a sunny Saturday when I booked for a local outdoor wedding. The couple wanted a casual, fun vibe, and our food truck seemed like the perfect fit. In my excitement, and maybe a bit of overconfidence, I glanced over my usual planning checklist. I figured I knew the ropes well enough by now. Big mistake.

First off, I underestimated the guest count. The couple said about 100 people, so I prepared for that number without leaving any room for error. I didn’t account for the possibility of unexpected guests. And sure enough, the final turnout was closer to 120. That should have been my first clue to always expect the unexpected. I should have also explained to the couple that it’s better to have too much food, than not enough at a wedding.

A classic wedding with a food trailer photo.

The menu was simple – gourmet burgers, fries, and a selection of sodas and lemonades. To make matters worse a few guests came back for seconds without me noticing it. I never distributed meal cards to limit the dining. This meant only 90 or so guests out of 120 were provided a full meal.

By 7 PM, my heart sank as I saw the supplies dwindling far faster than anticipated. The buns were the first to go, followed by the patties. We were down to our last bag of fries before I knew it. Panic set in as I realized we might not have enough to feed everyone. That’s when I learned the hard lesson about rounding up and planning for extra, especially for long events.

But the trouble didn’t stop with the food. Amidst the chaos, a guest approached the truck with a special dietary request. She was gluten intolerant and asked if we had anything that could accommodate her needs. My heart dropped. In my hasty preparation, I had completely overlooked dietary restrictions. I had nothing to offer her but a sincere apology. She was gracious, but the disappointment on her face was a gut punch I felt deeply.

As the night drew to a close, I had to face the music. We ran out of food, and not everyone was fed. The bride and groom were understanding but clearly disappointed. The feeling of letting them down on their special day was tough, but I did learn an important lesson about catering that I would apply moving forward.

That event was a turning point for me. I learned the hard way that no matter how experienced you think you are, you can’t cut corners. Preparation is key. I now follow my checklist religiously, no matter how small or casual the event might seem. I make sure to account for every guest, prepare for extras, and always, always cater to dietary needs.