Starchy potatoes (Russet, Maris Piper) make the fluffiest mash; waxy potatoes make a creamier, denser one. A medium potato weighs about 170–200 g (6–7 oz). Warm the milk and butter before adding them.
How to use the How Much Mashed Potatoes per Person Calculator
- Number of people
- Portion
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the number of people and the portion size.
Inputs explained
| Field | What to enter |
|---|---|
| Number of people | A number |
| Portion | Choose one: Small side (⅔ cup), Standard (⅞ cup), Hearty (1 cup), Very hearty (1¼ cups) |
What each result means
- Mashed potatoes = [Number of people]×[Portion]×236.5882365
- Mashed potato weight = [Number of people]×[Portion]×210
- Raw potatoes to buy = [Mashed potato weight]÷1.35÷0.85
- Medium potatoes (about 7 oz each) = ceil([Raw potatoes to buy]÷200)
- Milk or cream = [Mashed potato weight]÷1.35×0.25
- Butter = [Mashed potato weight]÷1.35×0.1
Example values
How the main result changes when Number of people changes and everything else stays at the example values above:
| Number of people | Raw potatoes to buy (lb) |
|---|---|
| 5 | 1.8 |
| 7.5 | 2.6 |
| 10 | 3.5 |
| 12.5 | 4.4 |
| 15 | 5.3 |
| 20 | 7.1 |
Formula
Mashed potatoes = people × portion (¾–1 cup ≈ 160–210 g)
Peeled cooked potatoes ≈ mashed ÷ 1.35; raw unpeeled potatoes ≈ peeled ÷ 0.85
Milk ≈ 25% and butter ≈ 10% of the cooked potato weight
Worked example
Inputs — Number of people: 10; Portion: Standard (⅞ cup).
Results — Mashed potatoes = 8.8 cups; Mashed potato weight = 4.1 lb; Raw potatoes to buy = 3.5 lb; Medium potatoes (about 7 oz each) = 9; Milk or cream = 1.44 cups; Butter = 136.1 g.
Frequently asked questions
How much mashed potato per person?
About ¾–1 cup (6–8 oz) per adult as a side dish.
How many potatoes for 10 people?
About 3½–4 lb (1.6–1.8 kg) of raw potatoes.
How much milk and butter for mashed potatoes?
Roughly ¼ cup of milk and 1 tbsp of butter per medium potato.