How this instrument works
Feeding a group starts with one simple decision: how much of an ingredient does a single person typically eat? Once that per-person amount is settled, the total needed for any group size is just that amount multiplied by the headcount: total = people × amount per person. This calculator applies that logic specifically to potatoes, in kilograms, but the arithmetic underneath is the same one used for rice, punch, bread rolls, or pizza.
The per-person figure itself is not fixed by any formula; it depends entirely on context. A potato served as one side dish among several might call for a smaller amount per person than a stew or mash built around potatoes as the main event. This calculator does not guess that figure for you — it simply scales whatever per-person estimate gets entered, from a light side portion to a hearty main-course helping.
That makes the tool useful for more than potatoes alone. Anyone catering a shared meal faces the identical headcount-times-portion arithmetic, whether they're planning bowls of rice, cups of punch, or slices of pizza. Swap the per-person figure to match whatever is being served, and the same multiplication scales correctly for six guests, sixty guests, or six hundred.
- Enter your expected headcount in the Number of people field.
- Enter your chosen serving size, in kilograms, in the Potatoes per person (kg) field.
- Read Total potatoes needed (kg) for the amount to buy or prepare.
- Raise or lower Potatoes per person (kg) to reflect a side dish versus a potato-focused main course.
- Reuse the same two fields and formula for other shared ingredients by swapping in their own per-person amount.
Worked example — six guests at half a kilogram
Feeding 6 people at an estimated 0.5kg of potatoes each needs total = 6 × 0.5 = 3kg, the default case here. Scale up to a larger gathering of 20 people at a lighter 0.3kg each and the total comes to 20 × 0.3 = 6kg, more total weight from more guests despite the smaller individual portion.
At the smallest possible scale, a single guest budgeting 0.4kg needs total = 1 × 0.4 = 0.4kg; multiplying by a headcount of exactly one changes nothing, a useful check that the formula behaves sensibly at its simplest edge case.
Questions
How much potato should I plan per person?
This calculator does not set that figure for you, since it varies by context — a side dish typically needs less per guest than a potato-focused main course like a big pot of mash. A commonly used rough estimate for a side portion sits around 0.3 to 0.5kg per person; enter whatever figure fits your specific menu into Potatoes per person (kg).
Does this formula work for ingredients other than potatoes?
Yes. The underlying arithmetic, total = people × amount per person, is the same scaling logic used for rice, punch, bread rolls, or pizza slices at any shared meal. Swap in the per-person amount for whichever ingredient you're planning, and the multiplication scales correctly regardless of what's being served.
What happens to the total if I add more guests?
Total rises in direct proportion to headcount, since Number of people is a simple multiplying factor. Doubling the guest count while keeping the same Potatoes per person (kg) figure exactly doubles Total potatoes needed (kg), going from 6 guests at 3kg total toward 12 guests needing 6kg.
Why does 20 people at 0.3kg each need less than double the potatoes of 6 people at 0.5kg?
Because both headcount and portion size change at once. Six people at 0.5kg total 3kg, while 20 people at a smaller 0.3kg total 6kg, more total weight, since the larger headcount outweighs the smaller individual portion without simply doubling either starting figure.
Is this calculator only useful for large groups?
No, it works identically at any scale, including a single guest. One person budgeting 0.4kg needs a total of exactly 0.4kg, since multiplying by a headcount of one leaves the per-person figure unchanged. The same formula scales smoothly from one diner up to hundreds.
Should I account for peelings or waste in the per-person figure?
That choice is yours to make before entering a number; some cooks build a trimming allowance into their per-person estimate, others measure only the edible portion. Whichever convention gets used, enter it consistently in Potatoes per person (kg) and the total will scale to match.