How is the DayZ metabolism drain worked out?

DayZ

Metabolism Drain

In DayZ, neglected hunger and thirst kill more players than bullets do, and the rates at which they drain are hard to judge by feel.

Metabolism Drain

Energy now (0–5000)

Water now (0–5000)

Mostly

Body temperature

A fresh spawn starts at 600 of each; the stats top out at 5000.

5h 43m

Energy lasts

Until it drops below 300 and health starts to fall

5h 43m

Water lasts

Real time. Drain is fastest when a stat is full and about half as fast near empty; this assumes it scales evenly in between. Illness and vomiting are not included.

How the numbers are worked out

Energy and water both run from 0 to 5000, and both fall all the time: about 0.01 a second standing still, 0.1 walking, 0.3 jogging and 0.6 sprinting, up to twice that when the stat is full. Being cold burns another 0.2 to 0.45 energy a second on top. Enter where your stats are and how you will be moving, and the calculator works out how long each lasts before it drops below 300, the point where health starts to fall.

The formula

drain per second = activity rate × (1 + stat ÷ 5000) + cold drain (energy only)
activity rate: idle 0.01 · walk 0.10 · jog 0.30 · sprint 0.60 · cold +0.20 to +0.45
time until 300 = (5000 ÷ rate) × ln((a + b × now) ÷ (a + b × 300))

Common mistakes

Cold is the hidden cost. A survivor walking in the cold can burn through energy several times faster than one walking warm, because the cold drain is added to the movement drain. Dry off and warm up before a long trip, and eat before you set out rather than when the icon starts flashing.

A worked example

With 3,000 energy and 3,000 water, walking steadily, both last about five and three-quarter hours of real time before dropping below 300. Jogging the whole way cuts that to under two hours, and sprinting to under one. Walking while cold changes only the energy side: between roughly 1 hour 15 minutes and 2 hours 15 minutes, depending on how cold, while water still lasts the full five and three-quarters.

Why a full stomach empties faster

The drain is highest when a stat is full and about half that near empty, so topping up to 5000 buys less time than the number suggests: walking from full lasts about 8 hours 50 minutes, not twice as long as walking from 3,000. Eating little and often keeps you in the efficient middle, and well above the 300 line where health starts to suffer.

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