Mass limits the amount of equipment you can put on a ship or module. The total amount of mass of a ship or module setup cannot exceed its Maximum Mass stat, otherwise the game would refuse to allow you to build or refit to that setup.
Despite the physical meaning of mass, the total amount of mass of a ship has no impact on its manoeuvrability whatsoever.
All ships and modules have an Unladen Mass stat (which may be zero). This is the mass of the ship or module itself, without any equipment on it.
Each piece of equipment adds its Mass stat to the Unladen Mass. Some mass values are expressed in percentages, such as "% ship mass", "% module mass" and "% weapon mass", which instead add a percentage of the value of the amount it is referring to.
The order of addition is as follows: non-percentage values are accumulated first, then percentage values for weapon mass, and finally, percentage values for ship/module mass.
The total mass is calculated from this sum, rounded up to the nearest integer.
[Talon Frigate with Pulse Ray V, Focused Optics V and Rear Thrusters V] Unladen Mass: 138 t 1x Pulse Ray V: 160 t Total of ship before modifiers: 138 t + 160 t = 298 t 1x Focused Optics V: 40% weapon mass = 40% x 160 t = 64 t Total of ship after weapon modifiers: 298 t + 64 t = 362 t 1x Rear Thrusters V: 10% ship mass = 10% x 362 t = 36.2 t Total of ship after all modifiers: 362 t + 36.2 t = 398.2 t = 399 t (rounded up)
Extra: For a Mk II Talon Frigate, Rear Thrusters V would provides 10% x (1 - 12%) = 8.8% ship mass instead.
- If a ship or module's mass exceeds its Maximum Mass (most probably due to a game update), you can execute a refit regardless of whether your Ship Factory is busy (in the case of ships), has no time cost, and refunds resources if the total resource cost of the refit would be negative. This refit must bring the ship or module below its Maximum Mass or the game would not accept it.
- "% weapon mass" also takes the mass of hangar weapons, including squadrons, into account, but not spawners.