The exchange rate is the pack, not the food
Ninety pounds of vegetables in one-pound bags, frozen flat at an inch and a quarter thick and stacked at eighty per cent efficiency, occupies just under four cubic feet. The same ninety pounds in the same bags dropped in loose and settling at three inches thick occupies just under nine and a half. Nothing about the food changed. The freezer did not get smaller. The packs got fatter.
| Pack thickness, 8 x 6 in footprint | 90 one-pound packs, stacked at 80% | Pounds per cubic foot |
|---|---|---|
| 1.00 in | 3.13 cu ft | 28.8 |
| 1.25 in | 3.91 cu ft | 23.0 |
| 2.00 in | 6.25 cu ft | 14.4 |
| 3.00 in | 9.38 cu ft | 9.6 |
This is why the advice to freeze flat on a tray keeps coming up, and it is not really about freezing speed. It is about the fact that a slab stacks and a lump does not. A frozen slab is also a pack you can break a corner off, which a lump is not.
Rated volume and the volume you get
A seven cubic foot chest freezer does not give you seven cubic feet of packs. The compressor hump takes a corner, the hanging basket takes a layer you cannot stack under, the lid seal takes an inch off the top, and you need somewhere to put your hand. Seventy to eighty per cent of the rating is what people actually load, and the last few per cent of that is only reachable by taking everything out.
Then there is whatever is already in there. Most freezers are carrying a layer of things from previous years that nobody is going to eat and nobody is going to throw away, and that layer is usually the real reason this year does not fit.
Pack size is a household decision
One pound packs are more work, more bags and more labels than two pound packs, and they waste less because you take out what you use. The arithmetic is neutral on this — the total volume barely changes, because a pack of twice the weight is roughly twice the volume — so it comes down to how you cook. What is not neutral is the thickness, which you can change for free.
The label count is not a joke. Ninety packs is ninety labels, and an unlabelled freezer is the same thing as an empty one eighteen months later.
What is not on this page
No storage temperature, no keeping time, no judgement about whether anything is safe to eat. A freezer that loses power during a storm is a food-safety question for your state or local health authority and for a tested source such as the USDA, and there is no calculator answer to it. Running cost belongs to the appliance running cost calculator, and sizing a freezer for a household rather than for one harvest belongs to the refrigerator size calculator.
Questions people ask
How many pounds fit in a cubic foot of freezer?
There is no single answer, which is the point of the page. Flat one-inch slabs stacked tightly reach nearly thirty pounds per cubic foot; loose bags of irregular shape can fall below ten. The calculator works it out from your own pack dimensions and stacking efficiency and shows the density you achieved, which is the number worth comparing year to year.
Why does the calculator not use the whole rated volume?
Because a freezer never gives you its rating. Baskets, the compressor hump, the space under the lid and the room you need to get a hand in all come off, and seventy to eighty per cent is what people actually load. That share is a field you can change if your freezer is better or worse than that.
Does freezing flat really make that much difference?
On the same footprint, a pack an inch thick takes a third of the space of one three inches thick, and the pack count and the weight are unchanged. It is the largest single lever on this page and it costs nothing but a tray and some patience on the first night.
One pound packs or two?
The total volume is about the same either way, so the arithmetic does not decide it. What decides it is how much you use at a time, and how many labels you are prepared to write. Smaller packs waste less food and cost more work.
What happens if the power goes out?
That is a food-safety question and this page does not answer it. Your state or local health authority and a tested source such as the USDA are where to go, and the answer depends on how long the door stayed shut and how full the freezer was, neither of which is arithmetic.