Portion Size Calculator

How Much Food to Actually Buy

Under-catering leaves guests hungry; over-catering wastes money and food. Both come down to the same missing number: how much of a given item you need per person, multiplied by how many people are eating. Once that per-person figure is known — from a recipe, a catering guide, or your own experience — the total is pure multiplication.

The Formula

Total Food Needed = Servings × Portion Size per Person

Where This Matters

  • Event planning — calculating total quantities of a dish for a wedding, party, or office lunch.
  • Meal prep — buying the right amount of protein or produce for a week of prepped meals.
  • Catering quotes — cross-checking a caterer's proposed quantities against a standard per-person portion.

Common Per-Person Portion Guidelines

Typical serving sizes used in catering and meal planning
Food categoryTypical portion per person
Boneless meat/poultry main5–6 oz
Rice or pasta (cooked)½–1 cup
Salad (side)1–1.5 cups
Bread rolls1–2 rolls

These are general planning guidelines from common catering references; actual appetite varies by group and occasion.

How to Use This Calculator

  1. Enter the Number of Servings (people to feed).
  2. Enter the Portion Size per Person.
  3. Enter the Unit you're measuring in (e.g. oz, g, cups).
  4. Select Calculate to get the total amount of food needed.

Related Calculations

Once you know the total quantity, the Grocery Budget Calculator can help estimate cost, or use the Recipe Scaling Calculator to adjust an existing recipe to match.