Mass

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.

Calculations
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.

Example
[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.