dxter's Supremacy 1914 battle calculator - Help Page

Feel free to send issue and bugs reports to call.of.war.calc@gmail.com. I am new to Supremacy 1914 and still figuring out some of the details of the battle mechanics so let me know if something seems off. Changes and updates can be found here.


This is a tool to estimate the outcome of a battle in the game Supremacy 1914. In the game battles have some randomness, but here we try to estimate the average expected outcome, which may differ a bit from any particular in-game battle. In most cases this estimate should be reasonably close to the majority of in-game battles, but there are in-game cases where the random values are, by chance, extreme and can produce unexpected outcomes. If you see a large difference between the in-game result and the calc it is possible that it is due to such an extreme in-game battle. However, it is more likely that inaccurate input values were given to the calc, or that something was missed in the interpretation of the in-game battle. That being said, if you notice something in the calc that seems off feel free to let me know and I'll look into it.

To use this tool, input the troop types, counts, and HP for each army and fill in other relevant data. Leaving something out or misspecifying something can often result in large differences from the game result. To run the battle click one of the "Start Battle" buttons.

Below are descriptions of what different input settings mean. They are listed in the order they appear on the page.


There are always two armies or sides, A and B, representing two opponents fighting each other. If two stacks are attacking each other it makes a difference which side they are on. Army A will always attack first. Which stack attacks first can make a difference in the outcome of a battle so it is good to know which stack it is and put it in Army A. If you are unsure you can try switching sides and see how the results differ. Again, this only applies if both stacks are attacking each other. If, for example, a stack in one army is attacking a stack that is just defending, it will make no difference which side they are on.

Add stack

Click this button to add another stack of units to the battle.

Start Battle

Once you have all of your stacks set up click on of the "Start Battle" buttons to start the battle.

Stack Info

A Stack represents a group of troops that are together when you click them on the map. You can specify one or more stacks and each stack can have one or more unit types.

Attack targets

If you want a stack to attack an enemy stack, select the stack you want to attack from the drop-down. If you only want a stack to defend, then do not select an attack target. If a stack is being targeted it will be in defense mode, but it can simultaneously be attacking the same or a different stack. A stack doesn't have to be attacking anything. It can just be defending. However, if you do not explicity select a target for a non-air ranged unit (e.g. artillery or battleships) the closest valid enemy stack will be attacked. Also if a target isn't set for a ranged unit and it is itself being targeted by an enemy, it will attack that stack if it can, even if there is another valid target that is closer. A stack can be attacked by multiple other stacks. It is important to set these targeting options correctly. If a stack destroys its target it will look for another stack to attack that is in range.


One of the available terrain options must be selected for each stack. Note that the unit type must match the terrain. For example, infantry can't be in the air. Use unit type "convoy" to indicate a plane convoy on land. For transport ships, set the terrain to sea. Use patrol for planes on patrol missions. If a naval transport is disembarking use debark.

Transport ships

To specify that units should be considered transport ships that are not disembarking simply set the terrain to sea.

Disembarking units

Disembarking (debarking) units take normal damage instead of naval damage. If the debark terrain is selected for a stack, the stack will take normal damage. Only balloons and units that can be be ferried across the water can be in debark stacks.


For aerial patrols select "patrol" as the terrain. The patrol will do 4 ticks of 1/4 damage every round.


This is the drop-down menu on the stack row after the word "at". This can be an important setting when there are multiple stacks on a given side or when ranged units are involved. This is a simplified representation of in-game positions (in km) to allow distances between stacks to be calculated. Positions are represented on an imaginary line where the position of a stack on the line represents its relative distance from other stacks. For example, if one stack has 0 km and another has 50 km then the stacks are 50 km apart.

Melee is represented by two enemy stacks that have the same position. Usually, you can just leave the position at zero for melee stacks. In-game multiple enemy stacks within 5km of an attacker will take damage from (and deal defensive damage to) the attacker regardless of which stack the attacker is specifically attacking. Here we are just simplify it by putting all stacks involved in melee at the same position. All plane attacks are considered melee attacks since targets always deal defensive damage, so make sure planes are at the same position as their target(s) in the calc.

These positions have three main purposes.

  1. To discriminate between melee and range attack. In an attack beyond melee range (5 km) the ranged attacker will not receive defensive damage. If you want to simulate bombarding at range you must make sure the relative distances between stacks are greater than 5 km, otherwise they will fight as melee and the result will be different. Similar to melee battles, if a stack is being bombarded, any stacks at the same position as the target will also be hit. Note that plane attacks are considered melee because when the plane attacks it is at the same position as the target. If a plane is not at the same position as the specified target you will get a warning.

  2. To specify the relative distance between two or more range stacks (e.g. ships). For example, in a fight between a cruiser and a battleship the positions might determine whether or not the cruiser is close enough to fire at the battleship. As above for melee, for example, if you specify a cruiser to target a battleship and the distance is too far you will get a warning.

  3. Positions can be set to prioritize targeting switches for ranged units when a stack dies. For example, if stack A1 is targeting B1 and B1 dies, but side B also has stacks B2 and B3 in range, which of these will A1 target next? If the positions of B2 and B3 are different, then A1 will target the closer one. As an example, say you have a Cruiser at position 40 attacking a land unit at position 0, and the enemy also has a sub at position 50 and a sub at position 75. In this example, once the Cruiser kills the land units it will attack the sub at position 50, because 50 is closer than 75 to 40. Note that if a ranged unit is bombarded by another stack and a target was not specified by the user, it will attack that stack back even if there is a closer stack to it that is not attacking it.

If you don't explicitly choose a position it will default to zero. Enemy positions both at zero is normally how melee and air attacks are specified, but if there are enemy stacks at any position that is the same it will be melee. For example if opposing infantry stacks are both at position 40 they will still be at a distance of zero from each other and be in melee range.

Here are the ranges for the ranged units: Artillery:50, Railgun:150, Cruiser:40, Battleship:75

Fortresses and buildings

To account for protection from fortresses and the damage done to fortresses as the battle progresses, you must add a fortress building along with its level and HP. You should also add any other buildings that are in the province so the damage can be calculated accurately. If the province has buildings but no fortress it will make no difference in the battle. However, you can add buildings without a fortress if you want to estimate building damage.

Only a single stack at a given position should be assigned the buildings. All other land stacks at the same position as the stack assigned buildings (except aircraft transport) will inherit the same set of buildings. If the buildings include a fortress, all of these stacks will receive the fortification bonus. When any of these stacks are involved in an attack or defense the appropriate building damage will be applied. If multiple stacks are defending an attack the building damage will only be applied once. In general, it should work as in-game. Note that the only way for another one of your own stacks to be at the same province nexus as another stack, is for one to be attacking and the other defending, or for both to be attacking different targets.

If there is a stack at or near the same position that shouldn't receive the fortification bonus, such as an allies stack or a stack just outside the province nexus you can give it, assuming the buildings are at position 0 km, position 1, 2, or 3 km. That way they will still be within melee range for the battle, but won't recieve the fort protection.

If there is a fortress with other buildings it is a good idea to run the calculation multiple times with "Simulate Variance" checked. The battle results can vary dramatically when there is a fortress with other buildings. More and higher level buildings can lead to more extremes. The variance will also depend on how much damage the enemy can do to buildings. Without "Simulate Variance" the result will show the average expected result of the battle.

Add unit

Click this to add another unit to the stack.

Remove stack

Click this to remove the current stack.

Unit info

For each unit in your stack specify the unit type from the drop down.

Unit count

Enter the number of units of this type at the given level.

Hit points (HP)

Enter either:

1. The number of remaining hit points for this unit (e.g. 17.3), or
2. The percentage of the maximum HP followed by % (e.g. 85%).

If a unit is at max HP but you don't know exactly how many hit points it has you can just use 100%.

The hit points for each unit type in a stack can be found in the "Army Details" tab in-game.

Max Rounds

For plane strikes the calc will assume you are sending the same stack of planes to the target repeatedly until one side dies (just like any other battle), unless you set the "Max Rounds" parameter. To simulate a single bombing run set "Max Rounds" to 1. You may want to set the max rounds to 1 or some other number for any type of battle to see what will happen in a single round.

Update Counts

If this is checked the unit counts and HP values will be replaced with those that are left after the battle. This is particularly use in combination with Max Rounds as you can do one round at a time and see how the condition of the armies change round by round.

New Tab

If you check this the results of an attack will be opened in a new browser tab. This may be useful if you want to search for various optimal combinations but don't want to lose the results of previous tests.

Simulate Variance

If you check this the calculator with simulate randomness in the battle as is done in the game. Rerunning the battle a bunch of times with this enabled can give you an idea of the distribution of possible outcomes.

If buildings are specified this option will cause damage to buildings in a random way as is done in-game. See Fortresses and buildings for more info.

Unspecified values

If any of the requested unit values are missing (e.g. HP is missing or zero) that unit is ignored. If no unit entries are complete for a stack the whole stack is ignored. If the format of an input value is wrong (e.g. if you specify "10x" for the unit count) an error is produced.


The number of dead units of each type is indicated as well as the hit-points lost. Damage to buildings is also shown. A summary table of the overall battle is shown for each side that includes lost HP and time and resources required to rebuild the lost units. If the optional "Update Counts" is specified at the bottom, the unit count and HP input fields are replaced with resulting values.