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Production is how a country manufactures Equipment.png equipment, consumer goods, infrastructure, and buildings.


There are three types of factories:

  • Civilian factory Civilian factories: Construction (including repair), trade, and consumer goods.
  • Military factory Military factories: Infantry/artillery, armor, and aircraft.
  • Naval dockyard Naval Dockyards: Ships, Submarines and Convoys.

Civilian and military factories have a base output of 5. For military factories, this value is then multiplied by the Production efficiency.png Production Efficiency. Naval dockyards have a base output of 2.5, but always have a production efficiency of 100%.

The production formula is :

For example, at 50% Production efficiency.png Production Efficiency with a 10% Modifier on Factory Outpout, the production would be

The main output modifiers for military factories and naval dockyards are Concentrated or Dispersed industry technology, while civilian factories are mainly affected by Construction industry technology and the economy law.

Consumer goods[edit]

Depending on economic laws and National Spirits , a number of civilian factories will be occupied by producing consumer goods and are unavailable for construction or trade. This number is computed as a percentage of the total number of factories (but not naval dockyards), rounding upwards. Factories are counted even when they are damaged and can't produce anything.


Suppose the Civilian economy law is enabled (requiring 30% of factories dedicated to consumer goods) and no other modifiers apply. A country has 50 military factories, 50 civilian ones and 20 Dockyards. It will then have 30 (civilian) factories dedicated to consumer goods.

Strategic Implications

Due to the fact that naval dockyards do not modify the needed consumer goods, a nation is normally better off building naval dockyards before military factories. This is under the premise that the military equipment is not immediately needed.

Production lines[edit]

See also: Construction
for Production by Civilian Factories

Production of Military and Naval Factories is organized into production lines, each of which produces a single type of equipment at a time. Up to 15 factories may be assigned to a single production line, but you may have several lines producing the same item.

Production line legend sketch.png

Production efficiency.png Production Efficiency[edit]

Each Production Line has its own efficiency level which determines how good it is at producing its current Equipment.png equipment. The higher the efficiency, the faster the Production Line produces equipment, up to a maximum value. Running the same Production Line continuously increases its efficiency.

Production efficiency is always at least 10% and increases by a base efficiency gain of +0.25% per day up to a production efficiency cap, which starts at a base level of 50% in 1936. Both the daily gain and the cap can be increased by industry technology research and national focuses.

Production efficiency is tracked separately for each factory. Adding one or more new factories to an existing production line reduces production efficiency of the added factories. It is important to know that the factories already in the line do not lose efficiency - what they are making has not changed. Only the new factory has minimum efficiency. Also, switching a production line to a related type of equipment cancels production of the current unit and the time spent on it, and reduces its efficiency depending on how drastic the change:

  • -10%: Different variant of the same model (e.g. Panzer III Ausf. F -> Panzer III Ausf. G [variants of the German medium tank 1])
  • -50%: The direct upgrade of the equipment of the same type (e.g. Panzer III -> Panzer IV [German medium tank 1 to medium tank 2])
  • -70%: Different model of the same chassis or airframe (e.g. Panzer III -> StuG III [German medium tank 1 to medium tank destroyer 1])
  • -80%: Different unit of the same archetype (e.g. Panzer IV -> Tiger[German medium tank 2 to heavy tank 2])

Efficiency drops to the minimum of 10% for any other changes (e.g. Infantry Equipment 1 to Towed Artillery 1).

These effects can be reduced by researching Dispersed Industry I to IV.

Note that producing ships, subs and convoys using dockyards always has an efficiency of 100%. Although all time and resources spent on an incomplete ship is lost if the line changes to another ship, the dockyard is at 100% efficiency as it starts the new ship design.


Resources cannot be stockpiled — they flow directly to production with any excess resources being effectively wasted.

Each equipment requires resources to produce. Lacking sufficient resources will apply a factory output and production efficiency increase penalty of up to -90%, with each resource (as opposed to each unit of resource) being weighted evenly. For example, producing something that costs 2 Steel and 1 Oil while lacking Oil will result in a -45% penalty (rather than a -30% penalty). This penalty stacks multiplicatively with other modifiers.

There are six strategic resources.

Icon Resource Equipment
Oil.png Oil Planes, except Jet Engined
Tanks and Trucks
Rubber.png Rubber Planes
Aluminum.png Aluminum Planes
Support Equipment
Steel.png Steel Infantry Weapons and Support Equipment
Artillery, Anti-Air and Anti-Tank
Tungsten.png Tungsten Artillery and Anti-Tank
Medium Tanks
Jet planes
Chromium.png Chromium Heavy, Super-Heavy and Modern Tanks
Large ships (Carrier, Battleship and Battlecruiser)


Land divisions and air wings are not produced as atomic units. Instead, factories produce individual tanks, airplanes, and so forth. This equipment is then sent to fill out the country's land divisions and air wings. Unlike resources, equipment can be stockpiled. These stockpile can be viewed under the Logistics Tab.

Equipment Supplies
Anti-Air Anti-airAnti-air
Anti-Tank Anti-tankAnti-tank
Artillery ArtilleryArtillery
Infantry Equipment
Light Tank Light tankLight tank
Mechanized MechanizedMechanized
Medium Tank Medium tankMedium tank
Support Equipment

External Links[edit]

Spreadsheet: [Hearts of Iron IV Resource Distribution by Country]