File:Damage Up Rainmaker Roller Chart.png

Formula
All time values were calculated using frame data, and confirmed through testing.

First, damage values for all possible amounts of Damage Up are calculated. When attacking the Rainmaker's Shield, damage limits do not apply. For example, the Rapid Blaster is no longer limited to doing a max damage per shot of 99.9. Damage for Inkbrush and Octobrush varies wildly based on luck and on distance from the opponent; the highest chance of dealing critical damage happens when the player is at such a distance that the tip of the brush hits the opponent when swung. The highest critical base damage value observed for inkbrush is 52.5, and for Octobrush it is 69.3.

x = Ability Points = 10*Mains+3*Subs

D = Damage = [base damage]*(1+(0.99*x-(0.09*x)^2)/100)

Then the number of shots required to pop the Rainmaker's Shield at all possible amounts of Damage Up is calculated. The Shield has 1000 hit points, but many weapons have damage multipliers (M) applied when attacking the Shield. The ROUNDUP(,0) function is used to round values up to an integer, because there is never a fraction of a shot.

S = Shots Required to Pop Shield = ROUNDUP(1000/(D*M),0)

Frame data and S are then used to calculate the time it takes to pop the shield. F1 and F2 are divided by 60 so that the resulting values are in seconds. In Splatoon, there are 60 frames per second. One shot is subtracted from S, because F1 accounts for the time it takes for the first shot to be fired. In the interest of consistency and easier testing, the time it takes for shots to travel to the Shield is not accounted for; in reality, it will take a bit more time than shown on the graph unless the player is standing right next to the shield.

F1 = Frames between pressing the fire button and a glob of ink being flicked, specifically the glob of ink that will hit the Shield, not any other ink visuals that appear around the weapon as part of the attack animation.

F2 = Frames between each additional shot being flung. Rollers and brushes are semi-automatic weapons, so this value may vary.

T = Time Required to Pop Shield = (F1/60)+(S-1)*(F2/60)