What are the calculations to figure out how long someone can live in a sealed room of a certain volume? Please check mine. Let's say that the room is 30 feet by 20 feet by 8 feet, or 4800 cubic feet. I believe that high carbon dioxide levels will kill you before low oxygen levels will. Inhaled carbon dioxide is 0.04% by volume, exhaled is a bit over 4%. Inhaled oxygen is 21%, exhaled 15%, a difference of 6%. A person breathes about 6 liters per minute, or roughly 9000 liters/day or roughly 300 cubic feet/day. Thus that person will decrease room oxygen by 300 x 6% = 18 cubic feet/day. He will increase room carbon dioxide by 300 x 4% = 12 cubic feet/day. Comfortable carbon dioxide levels are less than 1000 ppm (parts per million) (0.1% of room air). Dangerous levels are above 10,000 ppm, especially above 30,000 ppm. Let's take 30,000 ppm (3% of room air) as our death point, although obviously that's arbitrary. 0.03 times 4800 = 144 cubic feet of carbon dioxide in the room would be deadly. 144 / 12 (cubic feet of CO2 exhaled per day) = 12 days to death in that sealed room. Originally there were 4800 (room cu ft) * 0.21 = 1000 cu ft of oxygen (rounded) After 12 days, 18 (cu ft/day of oxygen decrease) x 12 = 216 cubic feet oxygen lost. That leaves 784 cubic feet of oxygen in the room, or 784/4800 = a little over 16% oxygen in the air. While people will have symptoms at 15% or less, it would be rare to die with oxygen levels above 10%. So my conclusion is that in the above scenario, a person would die in around 12 days, and from carbon dioxide toxicity rather than oxygen deprivation. Are my calculations correct on this? Thanks.