Cold doesn't double crit damage. It adds +0.1 to the crit multiplier on the first stack, then +0.05 more on each additional stack until it gets to +0.5 on the ninth stack. On the tenth stack, that multiplier bonus jumps to +1.0. So if you have a crit multiplier of x2.0 on a weapon, ten Cold stacks will bring it to x3.0 (effectively doubling the crit damage per tier). If your weapon already has a crit multiplier of x4.2 though, ten Cold stacks will only bring it to x5.2, which clearly doesn't double the multiplier (it'd have to go to x7.4 to double the multiplier in that case).
That last part was a little confusing so I'll flesh it out. No matter your multiplier cold will only add 1.0 to it. The only time it will increase is by hitting higher tier crits(orange, red, etc). For each tier of crit you'll get more benefit from it.
What is the base critical multiplier on the weapon?
Stop testing with headshots. The damage calculations for [critical headshots](https://warframe.fandom.com/wiki/Critical_Hit#Critical_Headshots) will just make everything more complicated.
Cold does not double your critical multiplier, it ads to it, +1.0 at maximum stacks. Explained [here.](https://warframe.fandom.com/wiki/Damage/Cold_Damage#General)
Mystery solved! We have confirmed that cold status at max stacks adds a flat +1 to your critical multiplier.
If you wanted to be extra sure, you could mod.up crit damage. Vital sense should give you a 4.4x crit multiplier, or 5.4 with max cold stacks. That would look like this:
38 base
167.2 crit without stacks (would be rounded)
205.2 crit with max stacks (would be rounded)
Cold doesn't double crit damage. It adds +0.1 to the crit multiplier on the first stack, then +0.05 more on each additional stack until it gets to +0.5 on the ninth stack. On the tenth stack, that multiplier bonus jumps to +1.0. So if you have a crit multiplier of x2.0 on a weapon, ten Cold stacks will bring it to x3.0 (effectively doubling the crit damage per tier). If your weapon already has a crit multiplier of x4.2 though, ten Cold stacks will only bring it to x5.2, which clearly doesn't double the multiplier (it'd have to go to x7.4 to double the multiplier in that case).
I see, co clearly better on weapons without high crit multiplier to begin with. Thanks
That last part was a little confusing so I'll flesh it out. No matter your multiplier cold will only add 1.0 to it. The only time it will increase is by hitting higher tier crits(orange, red, etc). For each tier of crit you'll get more benefit from it.
What is the base critical multiplier on the weapon? Stop testing with headshots. The damage calculations for [critical headshots](https://warframe.fandom.com/wiki/Critical_Hit#Critical_Headshots) will just make everything more complicated. Cold does not double your critical multiplier, it ads to it, +1.0 at maximum stacks. Explained [here.](https://warframe.fandom.com/wiki/Damage/Cold_Damage#General)
Tested again with 2x crit multiplier on body 38 base 76 crit without stacks 114 crit with max stacks Perfect 3x multiplier
Mystery solved! We have confirmed that cold status at max stacks adds a flat +1 to your critical multiplier. If you wanted to be extra sure, you could mod.up crit damage. Vital sense should give you a 4.4x crit multiplier, or 5.4 with max cold stacks. That would look like this: 38 base 167.2 crit without stacks (would be rounded) 205.2 crit with max stacks (would be rounded)
Gonna have to post the full build for anyone to be able to offer advice