I built a massive underground warehouse in my bunker — here’s the math behind how long it could sustain people

I’m working on a long-term underground bunker build and recently finished a large warehouse area. I got curious and did some rough math on what the storage could actually sustain.

The warehouse contains about 83,160 blocks of storage, so roughly 83,160 m³. Using a rough average density for dry goods (around 0.75 t/m³), that comes out to about 62,000 tonnes of food.

With basic calorie assumptions (dry goods, ~2,500 kcal per person per day), that’s on the order of 245,000 person-years of food. For example, that’s roughly 1,500 years for 160 people, or about 136 years for 1,800 people.

It’s obviously simplified back-of-the-envelope math, but it was interesting to see how the scale plays out. Curious how others would estimate this.