How Much Food to Cook for Meal Prep

It multiplies three ways

Two people. One prepped lunch a day. Five days.

That's ten portions, not five — and almost everyone anchors on the day count and lets the other two fold in silently. It matters because everything downstream is built on it: the shopping, the containers, the size of pot you need, and how much of it will actually fit in the fridge.

Portions to make is people × meals per day × days. Get that right and the rest is conversion.

The plate weight isn't the shopping weight

Here's the part that quietly ruins a prep session.

Cooking changes the weight of food, and it changes it in opposite directions depending on the ingredient:

• Meat loses water and fat in the pan. It comes out lighter, so you have to buy more than the plate weight.
• Rice, pasta and pulses absorb water. They come out much heavier, so you buy considerably less.

Shop from the plate weight and you under-buy the protein and over-buy the starch on the same trip. That's why a meal prep session so often runs out of one thing while producing an absurd amount of another.

Raw food to buy does that conversion, and Difference between raw and cooked shows how far off you'd have been:

Yield	3,500 g cooked needs	You'd have been out by
75% (roasted meat)	4,667 g raw	1,167 g short
100% (no change)	3,500 g raw	—
300% (rice)	1,167 g raw	2,333 g over

Measure your own yield

Weigh the ingredient raw. Cook it exactly the way you normally do. Weigh it again.

Cooked ÷ raw × 100 is the figure to enter.

Published numbers for the same ingredient disagree, because the answer depends on the cut, the fat content, the variety and how hard you cook it. Measuring beats looking it up — and since you're cooking the thing anyway, it costs you almost nothing to find out.

Reading the scale:

• Below 100 — it loses weight. Buy more than the plate weight.
• Exactly 100 — nothing changes. Roughly true of a mixed meal, where losses and gains cancel out.
• Above 100 — it absorbs water. Buy less. A yield of 300 means a 180 g cooked portion started as 60 g.

Decide the freezer split before you cook

Freezing stops the clock. It doesn't turn it back.

A portion that sat in the fridge for three days and then went in the freezer comes out having already used most of its life. If part of the batch was always going to be eaten later, it needed to be frozen while it was fresh.

Which means the split is a decision you make before you start cooking, not something you discover on Wednesday when there's more left than you expected.

That's why Portions for the fridge and Portions to freeze on cooking day are worked out up front, as part of the plan. Set the fridge window to zero and everything goes to the freezer; set it long enough and nothing does.

On how long cooked food keeps

This tool doesn't tell you, deliberately.

That's a food safety question, and your national food safety agency is the authority on it. The guidance is short, specific, freely published, and it differs a little between countries — so a calculator asserting a number would be both unnecessary and occasionally wrong for its reader.

Days you will eat from the fridge is yours to set from that guidance. What the tool contributes is the arithmetic that follows: how many portions that window covers, and how many therefore need freezing.

For a mixed meal, run it per component

A single yield figure for a plate of chicken, rice and vegetables is an average of three quite different numbers, and averaging them loses exactly the information you needed.

If you want it accurate, run the tool once per component — each with its own cooked portion size and its own yield — and add the shopping figures up. Portions to make stays the same across all of them, so only the weights change.

For a one-pot meal, a single run is fine. Raw weight per portion is handy here too: it lets you scale a single serving up or down without redoing the whole batch.

Before you start

Two practical checks that are easier to answer now than mid-cook:

• Total cooked weight — does your fridge have room for the portions that are staying in it?
• Do you have that many containers, clean, right now?

Both are cheap to check in advance and genuinely annoying to discover with a hot pan in your hand.