Damage Calculations

Damage Formula

[math]\displaystyle{ \text{Damage} = \left [ \left [ \left [ \text{Atk}_\text{cap} \times \text{Mod}_\text{post}\right]\times \text{Crit}\right]-\text{Armour}\right]\times \text{Ammo} }[/math]

• [math]\displaystyle{ \text{Atk}_\text{cap} }[/math] is the Cap Adjusted Attack Power
• [math]\displaystyle{ \text{Mod}_\text{post} }[/math] is any post-cap modifiers that are applicable.
• [math]\displaystyle{ \text{Crit} }[/math] is the critical strike modifier.
• [math]\displaystyle{ \text{Ammo} }[/math] is the remaining ammunition modifier.
• [math]\displaystyle{ \text{Armour} }[/math] is the armour of the target.

Where, Cap Adjusted Attack Power is Basic Attack Power that has been adjusted by applying the damage cap.

[math]\displaystyle{ \text{Atk}_\text{cap} = \text{Cap} + \sqrt{\left [ \text{Atk}_\text{basic} \times \text{Mod}_\text{pre}\right]-\text{Cap}} }[/math]

• [math]\displaystyle{ \text{Cap} }[/math] is the damage cap relevant to the phase.
• [math]\displaystyle{ \text{Atk}_\text{basic} }[/math] is the basic attack power of the relevant attack.
• [math]\displaystyle{ \text{Mod}_\text{pre} }[/math] is any pre-cap modifiers that are applicable.

Important Notes

• Pre- and post-cap multipliers are multiplicative.
• Results are rounded down to the nearest whole number. I.e. 4.2 → 4.

Basic Attack Power Formulas

The following formulas only apply to single fleets. Please see Combined Fleet, Land-Based Air Squadron and Support Expeditions for more details.

Important Notes

• Please see Akashi List for upgrade bonus values.
• [math]\displaystyle{ \text{FP} }[/math] is the firepower of the ship including equipment.
• [math]\displaystyle{ \text{TRP} }[/math] is the torpedo power of the ship including equipment or plane.
• [math]\displaystyle{ \text{ASW} }[/math] is the anti-submarine power of the ship or equipment.
• [math]\displaystyle{ \text{DB} }[/math] is the dive bombing power of the plane.
• [math]\displaystyle{ \bigstar }[/math] is the upgrade bonus of the equipment.

Bombing

This applies to both jet assaults and airstrikes.

[math]\displaystyle{ \text{Bombing Power} = \text{Type} \times \left[ \left[ \left[ \text{DB}\ OR\ \text{TRP} + \bigstar \right] \times \sqrt{\text{Count}_\text{Plane}}\right] + 25\right] }[/math]

• [math]\displaystyle{ \text{Type} }[/math] is a multiplier based on the type of the plane. See below for details.
• [math]\displaystyle{ \text{Count}_\text{Plane} }[/math] is the number of planes performing the attack.

Type	Multiplier	Notes
Torpedo Bombers	0.8x or 1.5x	The multiplier is chosen randomly. The chance is roughly 50%.
Dive Bombers Seaplane Bombers Fighter Bombers	1.0x
Jets (During jet assault)	1.0x
Jets (During normal bombing)	0.7071x

Important Notes

• Bombing power is calculated independently for each equipment slot on the carrier.
• The firepower of the carrier does not affect bombing power.
• The power is calculated after the air combat and anti-air fire phases which means bombers getting shot down will affect the final calculation.
• It is not affected by engagement, formation or damage states.
• It is affected by contact.

Surface Shelling

[math]\displaystyle{ \text{Shelling Power} = \text{FP} + \bigstar + 5 }[/math]

Important Notes

• The caliber of the gun does not affect damage.
• Abyssal installations that are not equipped with a plane that has a torpedo or dive bombing stat will use the surface shelling formula for calculating damage.

Carrier Attacks

[math]\displaystyle{ \text{Power}_\text{carrier} = \left[ \text{FP} + \text{TRP} + \bigstar + \left[ \text{DB} \times 1.3 \right] \times 1.5 \right] + 55 }[/math]

Important Notes

• Slot sizes and remaining plane count does not affect carrier attack power during shelling.
• If a carrier is not equipped with any torpedo or dive bombers, she will not participate in shelling.
  • This also applies if they have lost all bombers during the aerial combat phase.
• Carriers have the easiest time hitting the damage cap. This makes them very powerful assets for the fleet.
• Abyssal installations equipped with a plane that has a torpedo or dive bombing stat will use the carrier formula for determining shelling damage.

Torpedo Attacks

[math]\displaystyle{ \text{Torpedo Power} = \text{TRP} + \bigstar + 5 }[/math]

Important Notes

• Submarines and Abyssal installations cannot be targeted by torpedoes.
  • If the only available targets are submarines or installations, the attack will trigger but always miss.
• A ship must have a base torpedo stat of more than 0 to perform torpedo attacks.

Anti-Submarine Warfare

[math]\displaystyle{ \text{ASW Power} = \left[ \sqrt{\text{ASW}_\text{ship}} \times 2 + \text{ASW}_\text{equip} \times 1.5 + \bigstar + \text{Type}_\text{ship} \right] \times \text{Mod}_\text{synergy} }[/math]

• [math]\displaystyle{ \text{Type}_\text{ship} }[/math] is a constant depending on the type of the ship performing the attack. See below for details.
• [math]\displaystyle{ \text{Mod}_\text{synergy} }[/math] is the synergy multiplier bonus from using certain combinations of ASW equips. See below for details.

Ship Type Constant

Constant	Ship Types
13	Destroyer Escorts, Destroyers, Light Cruisers, Oilers (without seaplane bombers, torpedo bombers or rotary-wing aircraft equiped)
8	Aviation Cruisers, Aviation Battleships, Seaplane Tenders, Light Carriers, Landing Ships, Oilers (with seaplane bombers, torpedo bombers or rotary-wing aircraft equiped)

ASW Synergy Bonus

Equipment Combination	Bonus
Depth Charge + Depth Charge Projector + Sonar	1.4375x
Depth Charge Projector + Sonar	1.15x
Depth Charge + Sonar	1.15x
Depth Charge + Depth Charge Projector	1.1x

• The bonuses do not stack.
  • The exception is when using the special depth charge projectors detailed below.
• There is an accuracy bonus as well but it is small. Stacking sonars will give a bigger accuracy bonus.
• The breakdown of equipment types are:
  • Sonars: Type 93 SONAR, Type 3 SONAR, Type 0 Passive SONAR, Type 4 SONAR, Type124 ASDIC, Type144/147 ASDIC, HF/DF + Type144/147 ASDIC
  • Depth Charge Projectors: Type 94 Depth Charge Launcher, Type 3 Depth Charge Launcher
  • Depth Charges: Type 95 Depth Charge, Type 2 Depth Charge
• The Type 3 Depth Charge Launcher (Concentrated Deployment), Prototype 15cm Nonuple ASW Rocket Launcher, Type 2 12cm Mortar Kai and Type 2 12cm Mortar Kai (Concentrated Deployment) do not count as depth charge projectors for the DC+DCP+Sonar synergy bonus.
  • They do still count for the DCP+Sonar synergy bonus.
  • Because they do not count, the DCP+Sonar bonus with these equips stack with the other DC+DCP+Sonar bonus.
  • This is only possible with a ship that has 4 equipment slots.

Important Notes

• ASW power is heavily influenced by equipment ASW.
  • Having better ASW equipment is better than increasing ship ASW.
• Accuracy during night battles is abysmal making it impossible to damage submarines at night.
  • This does not apply to night battles in a Combined Fleet.
• It is possible to perform opening ASW attacks when certain conditions are achieved. For more details, please see Opening Anti-Submarine Warfare.
  • You should prioritise reaching OASW thresholds over synergy bonuses.

Surface Night Battle

[math]\displaystyle{ \text{Night Battle Power} = \text{FP} + \text{TRP} + \bigstar + \text{Contact}_\text{NB} }[/math]

• [math]\displaystyle{ \text{Contact}_\text{NB} }[/math] is the Night Battle Contact constant of +5 if triggered.

Important Notes

• Night battle is unaffected by engagement.
• If a night battle special attack is evaded, chip damage is applied instead.
• Graf Zeppelin, Base Saratoga, Taiyou Kai Ni, Ark Royal (with Swordfish use the surface night battle formula if they are not performing a carrier night attack.
• In night battle versus Abyssal installations, the torpedo stat is not counted.
  • This also means any upgrade bonuses to torpedo power is ignored.

Carrier Night Attacks

[math]\displaystyle{ \text{Night Battle Power}_\text{carrier} = \text{FP}_\text{ship} + \text{FP}_\text{night plane} + \text{TRP}_\text{night plane} + \text{DB}_\text{night plane} + \sum{\text{Night Plane Bonus}} }[/math]

Where, the Night Plane Bonus is:

[math]\displaystyle{ \mathrm{A} \times \text{Count}_\text{plane} + \mathrm{B} \times \left[ \text{FP}_\text{night plane} + \text{TRP}_\text{night plane} + \text{DB}_\text{night plane} + \text{ASW}_\text{night plane} \right] \times \sqrt{\text{Count}_\text{plane}} + \sqrt{\bigstar} }[/math]

• [math]\displaystyle{ \mathrm{A} }[/math] is 3 for night planes; and 0 for Swordfish, Zero Fighter Type 62 (Fighter-bomber/Iwai Squadron) and Suisei Model 12 (w/ Type 31 Photoelectric Fuze Bombs)
• [math]\displaystyle{ \mathrm{B} }[/math] is 0.45 for night planes and 0.3 for Swordfish, Type 62 Iwai and Photobomb Suisei.

Important Notes

• Carriers must be equipped with a Night Operation Aviation Personnel or Night Operation Aviation Personnel + Skilled Deckhands in addition to night attack capable planes in order to perform carrier night attacks.
  • Exceptions to this are Saratoga Mk.II and Akagi Kai Ni E that only need night attack capable planes.
• If the carrier night attack is evaded, it deals chip damage instead.
• Unlike daytime carrier attacks, it is possible to attack even if no bombers are equipped.
  • You still need night fighters to trigger the attack.
• Like daytime carrier attacks, carriers are unable to attack if moderately damaged or worse.
  • Armoured carriers are only disabled at heavy damage.
  • Carriers that can use the night battle shelling formula will use that instead if moderately damaged.
• The formula only takes into account the base stats of the carrier and night attack capable planes equipped (includes upgrade bonuses from night capable planes).
  • This means any other stats and upgrade bonuses from equipment like guns and non-night capable planes are ignored.

Anti-Installation Attacks

[math]\displaystyle{ \text{Anti-Installation Power} = \text{Atk} \times \text{Mod}_\text{A} + \text{Mod}_\text{B} }[/math]

• [math]\displaystyle{ \text{Atk} }[/math] is the basic attack power of shelling, carrier attacks, night battle or carrier night attacks with the torpedo stat ignored.
• [math]\displaystyle{ \text{Mod}_\text{A} }[/math] are the multiplicative anti-installation bonuses. See below for details.
• [math]\displaystyle{ \text{Mod}_\text{B} }[/math] are the additive anti-installation bonuses. See below for details

Multiplicative Bonuses

Equipment Name	Artillery Imp		Isolated Island Demon		Soft-Skinned
	Single	Multiple	Single	Multiple	Single	Multiple
Anti-Aircraft Shells	-		1.75		2.5
Armour-Piercing Shells	1.85		-		-
WG42 (Wurfgerät 42)	1.6	2.72	1.4	2.1	1.3	1.82
Shipborne Model Type 4 20cm Anti-ground Rocket Launcher	1.5	2.7	1.3	2.145	1.25	1.875
Mortars	1.3	1.95	1.2	1.68	1.2	1.56
Landing Crafts	1.8		1.8		1.4
Toku Daihatsu-class Landing Craft	1.15		1.15		1.15
Daihatsu-class Landing Craft (Type 89 Medium Tanks & Marines)	1.5	2.1	1.2	1.68	1.5	1.95
Toku Daihatsu Landing Craft + 11th Tank Regiment	1.8		1.8		1.8
Landing Craft Upgrade Bonus	[math]\displaystyle{ 1 + \dfrac{\left( \text{Average Landing Craft}\ \bigstar \right)}{50} }[/math]
Type 2 Ka-Mi Tank	2.4	3.24	2.4	3.24	1.5	1.8
Tank Upgrade Bonus	[math]\displaystyle{ 1 + \dfrac{\left( \text{Average Landing Craft}\ \bigstar \right)}{30} }[/math]
Dive Bombers	1.4		1.4		-
Seaplane Bombers Seaplane Fighters	1.5		-		1.2
Destroyers Light Cruisers	1.4		-		-

Additive Bonuses

Equipment Name	Number Equipped
	1	2	3	4
WG42 (Wurfgerät 42)	75	110	140	160
Shipborne Model Type 4 20cm Anti-ground Rocket Launcher	55	115	??	??
Type 2 12cm Mortar Kai	30	55	75	??
Type 2 12cm Mortar Kai (Concentrated Deployment)	60	110	??	??
Toku Daihatsu Landing Craft + 11th Tank Regiment	25	-	-	-

• Question marks indicate values that haven't been tested.

Important Notes

• For the Toku Daihatsu, T98+Marines and 11th Tank Regiment, they get both the regular Daihatsu bonus and their own special bonus.
• All multipliers used in determining anti-installation power are pre-cap.
• The amount of multipliers available make even low firepower ships like destroyers viable anti-installation ships.

Attack Power Corrections

After calculating the basic attack power of the attack being made, it is then adjusted based on various factors. Attack power modifiers can be split into pre- and post-cap modifiers. Post-cap modifiers are more powerful to have because they aren't reduced by the cap.

Attack Power Cap

The attack power cap varies depending on the phase of combat it is in.

• Support, ASW, opening and closing torpedo - 150
• Day shelling - 180
• Night battle - 300

Important Notes

• Any excess firepower above this cap is square rooted. Please see the damage formula for how it is applied.
• It is still worth aiming to go above the attack power cap because some pre-cap modifiers can severely reduce your attack power.

Pre-cap Modifiers

Engagement

For more details on engagement, please see Engagement Form.

Form	Damage Modifier	Chance	Chance with Saiun
Parallel Engagement 同航戦 (Doukousen, 同航戦?)	100%	45%	45%
Head-on Engagement 反航戦 (Hankousen, 反航戦?)	80%	30%	40%
Crossing the T (Advantage) T字戦有利 (T Ji-sen Yuuri, T字戦有利?)	120%	15%	15%
Crossing the T (Disadvantage) T字戦不利 (T Ji-sen Furi, T字戦不利?)	60%	10%	0%

• All engagement forms affect both sides equally, including crossing the T (Advantage or Disadvantage).
• Night battle and aerial combat are not affected by engagement.
  • The exception to this are night battle nodes.
• OASW and opening torpedoes are affected by engagement even though it is only displayed after those phases.
• Equipping a Saiun effectively makes what would have been Crossing the T (Disadvantage) become Head-on engagement.

Important Notes

• It is useful in some situations to not take the Saiun in order to get Crossing the T (Disadvantage). This is because it can hamper the enemy from damaging your fleet as much as it hampers yours.

Formation

For more details on formation, please see Formation Selection.

Formation Attack Power Modifiers

Formation	Shelling	Torpedo	Anti-Submarine	Night Battle
Line Ahead 単縦陣 (Tanjuu-jin, 単縦陣?)	100%	100%	60%	100%
Double Line 複縦陣 (Fukujuu-jin, 複縦陣?)	80%	80%	80%	100%
Diamond 輪形陣 (Rinkei-jin, 輪形陣?)	70%	70%	120%	100%
Echelon 梯形陣 (Teikei-jin, 梯形陣?)	75%	60%	110%	100%
Line Abreast 単横陣 (Tan'ou-jin, 単横陣?)	60%	60%	130%	100%
Vanguard 警戒陣 (Keikai-jin, 警戒陣?)	50%	100%	100%	50%
	100%	100%	60%	100%

Damage State

Damage State	Shelling	Torpedo	Anti-Submarine
Lightly Damaged (小破)	100%	100%	100%
Moderately Damaged (中破)	70%	80%	70%
Lightly Damaged (大破)	40%	0%	40%

Important Notes

• Damage state does not affect aerial combat.
  • It will affect carrier attacks in the shelling phase.

Night Battle Special Attacks

For more details please see Night Battle Special Attacks.

Type		Modifier	Attacks	Notes
Cut-In	3x Main Gun	2	1
	2x Main Gun 1x Secondary Gun	1.75	1
	2x Torpedo	1.5	2
	1x Main Gun 1x Torpedo	1.3	2
	1x Torpedo Skilled Lookout LoS RADAR	1.2	1	Destroyers only.
	1x Main Gun 1x Torpedo LoS RADAR	1.3	1
	1x 12.7cm D Kai 1x Torpedo LoS RADAR	1.625	1
	1x Torpedo	1.75	2	Submarines only. Only works with the Late Model Bow Torpedo Mount (6 Tubes) and Skilled SONAR Personnel + Late Model Bow Torpedo Mount (6 Tubes).
	2x Torpedo	1.6	2
Double Attack		1.2	2
Normal Attack		1.0	1

Carrier Night Attacks

For more details please see Carrier Night Attacks.

Type		Modifier	Notes
Cut-In	2x Night Fighter 1x Night Bomber	1.25
	1x Night Fighter 1x Night Bomber	1.2
	3x Night Fighter	1.18
	2x Night Fighter Other
	Night Fighter Night Bomber Other
	Night Fighter 2x Other
Normal Attack		1.0

• "Other" referrs to Swordfish, Zero Fighter Type 62 (Fighter-bomber/Iwai Squadron) and Suisei Model 12 (w/ Type 31 Photoelectric Fuze Bombs).

Gun Fit Bonuses

Unlike the other pre-cap bonuses, this is just an additive firepower bonus added for light cruisers and Italian heavy cruisers when equipped with certain guns. The bonus is minor, please refer to the gun fit bonuses for more details.