# MechWarrior Online Heat Ratio Guide

MechWarrior Online Heat Ratio Guide by ZodiacX

As the title suggests, this guide is intended to go over the concept of heat ratios and how to use that knowledge when building your mech. It should be noted that this guide assumes nominal heat sink dissipation, and disregards the environmental effects of caustic valley and frozen city.

The “Standard” Heat Ratio:
This heat ratio calculates a linear ratio of heat generation vs dissipation and is calculated by the following formula:

[Heat Ratio] = 10 * [Heat per Second] / [Heat Sinks]

[Heat per Second] is the summation of the of the Heat per Second value of all weapons you are firing in a group. In general, you should use your alpha-strike value (the total from all equipped weapons). [Heat Sinks] is the number of equipped heat sinks, nice and simple. The reason that this formula has a factor of 10 is because a standard heat sink dissipates 0.1 heat per second, so it takes 10 seconds for 1 heatsink to dissipate 1 heat.

Interpretting the “Standard” Alpha-Strike Heat Ratio:

[Heat Ratio] <= 1.0

A heat ratio of 1 is a perfect balance of heat generation to dissipation. So any value less than one signifies being able to fire non-stop without any worries of overheating. However, in mechwarrior online this would be excessive as rarely will you end up firing non-stop for more than a minute.

1.0 < [Heat Ratio] < 1.5

This is an optimal heat ratio range if you plan to be firing for extended periods of time. This means those assault class mechs who stand toe-to-toe with their opponents and LRM boats who fire as long as they have a viable lock. This will range of heat ratios will accumulate some heat, but should allow you to cool sufficiently when changing targets and lining up shots.

1.5 < [Heat Ratio] < 2.0

This heat ratio range is going to be more useful for those who don’t commit to a single target and fire like there’s no tomorrow. An example is light and medium mechs who will be using the terrain to bob-and-weave, shooting their opponents then running around to fire from another angle. You should still be able to stand-off for brief moments but you won’t be wanting to fire continuously for too long.

2.0 < [Heat Ratio] < 2.5

This range should be reserved for the more experienced pilots with stricter fire-discipline. The use of missiles and high-caliber energy weapons will generally push you into this range. However, effective use of weapon groupings can prevent overheating: ie) Short-range energy weapons for close engagements and LRMs for long-range fire will generally not be fired together.

2.5 <= [Heat Ratio]

This range is dangerous to try to run except for expert pilots. You will not be able to effectively sustain fire unless you have very specific weapon groupings being cycled. Even so, this generally means you have too many weapons and should probably rework your build.

The MWO Mechlab Heat Ratio:

This heat ratio is non-linear and therefore is a little harder to interpret. The formula has been calculated be approximately:

[Heat Ratio] = 0.61 * sqrt( [Heat Sinks] / [Heat per Second] )

Note that the ratio of [Heat Sinks] to [Heat per Second] is flipped relative to how the “Standard” Heat Ratio uses them. This is important as it signifies a reverse trend in the MWO mechlab. Below is a table which provides a correlation between the “Standard” and MWO Heat Ratios.

Other Heat Notes:
You will run hotter on caustic.
You will run cooler on frozen valley.
Double heat sinks theoretically are twice as efficient as single heat sinks.
Any heat sinks in your legs will be twice as efficient when standing in water.
For a more in-depth discussion on the heat mechanic used in the game follow MechWarrior Online Heat Mechanics Guide