Units
The following units are important in Factorio.
Power
Power is defined as work being done per unit of time.
Watt (W)
The basic unit of power is 1 watt (W), which is defined as 1W = 1J / 1s, ie. one Joule of work being done every second.
The game commonly deals with larger units, namely kilowatts (kW) and megawatts (MW).
Lamps use 5kW while turned on. A Radar uses 300kW while active - equivalent to 60 lamps. One Steam engine is capable of outputting 510W.
Work
Work is defined as a transfer of energy, or as energy being "spent".
Joule (J)
The basic unit of work is 1 joule (J), and represents the work being done (total energy transferred) by a power of one watt applied for one second: 1J = 1W * 1s.
In-game, every piece of coal burned will produce 8kJ. One Accumulator is capable of storing 5MJ.
Time
Second (s)
One second in-game. This is not guaranteed to correspond to one real second. For example, slow computers may not manage to calculate an entire tick during the corresponding real time frame of 1/60th of a second.
Day
A day has 25000 Game-ticks or 416.66 game-seconds (= 6.94 Game-minutes).
This is the cycle (realtively speaking)
0.75 -> 0.25 (half a day), 100% bright - 208.33 secs 0.25 -> 0.45 getting dark (evening) - 83.33 secs 0.45 -> 0.55 night - 41.66 secs 0.55 -> 0.75 get light (morning) - 83.33 secs
------------- day -------><--- evening ------><-night-><----- morning -----><-------- day -----------
% 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 |----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|
Distance
Tile
The tile is both used as a unit of distance/length and a unit of area. For example, the size of an object may be expressed as "2x2 tiles", which means the object covers an area of 4 square tiles or tiles². The unit of square tiles is often simplified into tiles.
Chunk
A chunk is a quadratic area where one side is 32 tiles long. (1024 square tiles)