File:Damage Up 2HKO+ Chart.png

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

Base damage of all charted weapons:
 * Rapid Blaster & Rapid Blaster Pro: 80
 * Sloshing Machine: 76
 * Slosher: 70
 * Tri-Slosher: 62
 * .52 Gallon & .96 Gallon: 52
 * Splattershot Pro: 42
 * H3 Nozzlenose: 41
 * Sploosh-o-matic: 38
 * Octobrush: 37
 * Hydra Splatling (full charge), Splattershot: 35
 * Jet Squelcher: 31
 * L3 Nozzlenose: 29
 * Inkbrush, Splattershot Jr., N-zap, Splash-o-matic, Dual Squelcher, Mini Splatling, Heavy Splatling, Hydra Splatling (partial charge): 28
 * Aerospray: 24.5

Limited at 99.9: Rapid Blaster & Rapid Blaster Pro.

Limited at 49.9: Splattershot Pro & H3 Nozzlenose.

Limited at 33.3: Jet Squelcher, L3 Nozzlenose, Dual Squelcher, Heavy Splatling, Hydra Splatling (partial charge), Inkbrush, Mini Splatling, N-zap, Splash-o-matic, Splattershot Jr.

Limited at 24.9: Aerospray.

All other weapons have a limit, but do not reach it.