Accuracy, Evasion, and Criticals are three mechanics intertwined together, representing the ability of a ship to hit another one. The formulas presented on this page are still subject to change as more testing is done.
Please note that all formulas between [math]\displaystyle{ \lfloor \ \rfloor }[/math] are rounded down.
The hit rate is the probability of an attack hitting the target. It's the same for all attacks as well as abyssals. It stems from the difference between the Accuracy of the attack and the evasion of the target.
[math]\displaystyle{ \text{Accuracy}_\text{atk} }[/math] the calculated accuracy of the attack. Please see below for the various accuracy formulas.
[math]\displaystyle{ \text{Evasion}_\text{post-cap} }[/math] the calculated evasion of the defending ship. Please see below for the evasion formula.
If negative, it is still applied the same way, increasing the hit rate.
[math]\displaystyle{ \text{Morale}_\text{defender} }[/math] the morale state modifier of the defending ship. Morale is referring to the value of attacking timing, not the value before entering battle. Please see Morale and Fatigue for more details.
Sparkled is 0.7,
Normal is 1.0,
Orange is 1.2,
Red is 1.4.
[math]\displaystyle{ \text{Acc}_\text{proficiency} }[/math] the average plane proficiency accuracy bonus. Please see Plane Proficiency for more details.
The average is calculated only from dive bombers, torpedo bombers, seaplane bombers and large flying boats.
Hit rate has an effective minimum of 11% and a maximum of 97%.
Plane proficiency is the only factor that allows a ship to go beyond 100% hit rate.
The effect of sparkle is reduced the closer Hit rate is to the caps.
Critical Hit Rate
Critical Hits are hits that do more damage than normal. The critical hit rate stems directly from hit rate with different proportion depending on the attack type.
[math]\displaystyle{ \text{Const}_\text{contact} }[/math] the night contact constant from Night Recons , its value depends on the stat of the if night contact is triggered, and 0 otherwise,
[math]\displaystyle{ \text{Hit}_\text{cap} }[/math] the Hit Rate Cap defined above,
[math]\displaystyle{ \text{Acc}_\text{proficiency} }[/math] the average plane proficiency accuracy bonus. Please see Plane Proficiency for more details.
The average is calculated only from dive bombers, torpedo bombers, seaplane bombers and large flying boats.
[math]\displaystyle{ \text{Crit}_\text{proficiency} }[/math] the plane proficiency critical bonus. See here for more details.
↑Carrier Night Air Attacks (NB CVCI) use the night battle Mod.
↑Based on KanColle Kai datamine, unconfirmed if also 0 like regular Airstrike in browser version
Hit Rate & Critical Roll
There is a single roll for both normal and critical hits.
For example, for a hit rate of 50% on a shelling attack, the crit rate is then 10%. The roll can be represented as followed:
Roll Example
Critical Hit 10%
Hit 40%
Miss 50%
The normal hit rate is 40% and the remaining 10% is the critical hit rate.
Notes
The effect of accuracy and sparkling on crit rate is limited
Because it stems directly from hit rate, it is also affected by the caps.
With low accuracy, a disproportionately high amount of successful hits will be "criticals".
With proficiency bonus it's possible to have a crititical rate above the hit rate, in this case the critical rate override the hit rate.[1]
Damage Animations
When a ship takes a hit, the game will display the damage animation following in 3 possible outcomes (e.g. with 25 damage):
miss (no damage),
25 (normal damage)
25 Critical hit! (critical damage).
However, the damage status displayed is mostly defined by the amount of damage dealt, and not the real damage status happening in the game.
Due to this, displayed critical hits and misses are rarely true critical hits or misses.
The displayed damage status is as follows:
Display Behavior
Damage Dealt
Damage Displayed
Miss
Miss displayed normally
0
Always displayed as a miss
≤14
Never displayed as Critical hit!
[15;39]
Criticals displayed normally
≥40
Always displayed as Critical hit!
Notes
A patch exists to fix this misleading behavior and display the real damage status, see here.
Accuracy
Below are the common variables used in all accuracy formulas:
[math]\displaystyle{ \text{Level} }[/math] is the level of the attacking ship.
[math]\displaystyle{ \text{Luck} }[/math] is the luck of the attacking ship.
[math]\displaystyle{ \text{Acc}_\text{equip} = \text{Acc}_\text{equip base} + \text{Acc}_\text{equip bonus} + \text{Acc}_\bigstar }[/math] is the total accuracy provided by an equipment, with:
[math]\displaystyle{ \text{Acc}_\text{equip base} }[/math] is the base accuracy of the equipment,
[math]\displaystyle{ \text{Acc}_\text{equip bonus} }[/math] is the visible accuracy bonuses,
[math]\displaystyle{ \text{Mod}_\text{vanguard} }[/math] is an accuracy malus when the opposite fleet is in Vanguard formation. See below for more details.
It is still unknown if this affects night battles, airstrikes, ASW, or LBAS.
[math]\displaystyle{ \text{Mod}_\text{morale} }[/math] is the morale modifier of the attacking ship. Morale is referring to the value of attacking timing, not the value before entering battle. See Morale and Fatigue for more details.
Because of the number of modifiers to accuracy in-game, it is not trivial to increase accuracy. Therefore it is more important to prioritize attack power (firepower, torpedo, ASW, airstrike, LBAS, ...).
It is inadvisable to run any of the other setups beyond the most basic Gun+AP. This is because the other set-ups will interfere with artillery spotting and cost better attack bonuses.
[math]\displaystyle{ \text{Acc}_\text{equip base} }[/math] does not include any Visible Bonus nor Improvement.
[math]\displaystyle{ \text{Mod}_\text{formation} }[/math] uses the same Day Shelling formation modifier as the sortieing fleet if Single vs Single combat, or 1.0 if the player fleet is Combined
Vanguard uses Top value (0.8) only, vs DD exception also applies
Player Single vs Enemy Combined is unconfirmed, but suspected to be 1.0 for all formations in line with Damage calculations
Torpedo Attacks
This formula only applies to opening and closing torpedo attacks during day battles.
This formula applies to the airstrikes performed during the aerial combat phase and support. Although ASW support functions like an airstrike for damage, it does not use this formula.
[math]\displaystyle{ \text{Acc}_\text{equip} }[/math] the accuracy stat of the plane.
[math]\displaystyle{ \text{Acc}_\text{Sp} }[/math] accuracy bonus for LBAS Special Bombers on some targets.
[math]\displaystyle{ \text{Mod}_\text{morale} }[/math] the morale modifier of the plane;
Normal/Orange morale: 1.0
Red morale: 0.8
[math]\displaystyle{ \text{Mod}_\text{CF} }[/math] being 1.1 if the enemy fleet is a Combined Fleet, 1 otherwise.
[math]\displaystyle{ \text{Acc}_\text{proficiency} }[/math] the plane proficiency accuracy bonus. See here for more details.
Unclear if applied here or after [math]\displaystyle{ \text{Hit}_\text{cap} }[/math]. If applying here, skip [math]\displaystyle{ \text{Acc}_\text{proficiency} }[/math] for hit rate.
[math]\displaystyle{ \text{Evasion}_\text{ship} }[/math] the displayed evasion of the ship, including any equipment stats and Visible Bonuses.
[math]\displaystyle{ \text{Mod}_\text{formation} }[/math] the formation modifier. It varies based on the attack being received. Please see Combat for more details.
Vanguard's modifier is 1.0 if assuming values described in Vanguard Formation
[math]\displaystyle{ \text{Mod}_\text{searchlight} }[/math] the Searchlights evasion penalty. It is 0.2 for any ship equipped with a searchlight (even if not triggered) and 1.0 otherwise.
[math]\displaystyle{ \text{Mod}_\text{sonar} }[/math] the gained from Sonars' Improvements, that only applies to opening and closing torpedo attacks. It is 0 otherwise.
[math]\displaystyle{ \text{Mod}_\text{CA} }[/math] the CA/CAV night battle evasion bonus. It is 5 for CA(V) during Night Battles and 0 otherwise.
[math]\displaystyle{ \text{Mod}_\text{DD} }[/math] the DD night battle evasion bonus. If the DD is equipped with a SurfaceSurface RadarAND a Skilled Lookout , then it is 10.
[math]\displaystyle{ \text{Mod}_\text{fuel} }[/math] the remaining fuel penalty:
[math]\displaystyle{ \text{Acc}_\text{Atk} }[/math] the standard accuracy described here
PT boats are "DDs" in the game, so the [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] for vanguard is 1.1 during shelling, and 1.2 during the torpedo phase.
Historical accuracy bonuses during Events are included in the Standard Accuracy Term, i.e. it is affected by the [math]\displaystyle{ \text{Mod}_\text{PT} }[/math] modifier.
[math]\displaystyle{ \text{EVA}_\text{PT} }[/math] the PT estimated evasion described bellow,
[math]\displaystyle{ \text{Mod}_\text{Ship} }[/math] the bonus given by ship types, described below,
[math]\displaystyle{ \text{Mod}_\text{EquipmentAcc} }[/math] the bonuses given by equipment, described below,
[math]\displaystyle{ \text{Mod}_\text{Night} }[/math] being 0.7 during night battle, 1 during day battle.
Amagiri Kai Ni/D has the ability to prioritize focusing on attacking PT imps with significantly increased accuracy if any are present.
DD placed in the composition slots above and below her will gain a noticeable accuracy boost and will prioritize attacking PT boats if any are present.
The PT boat targeting rate is 100% for all affected ships [9].
During Events, some special bonuses may be added, with "historical" ships and equipment gaining some accuracy bonuses[10].
of the attacking ship.
provided by an equipment, with:
Smoke Generators are used.
/
Interceptors, the 
stats are respectively "Anti-Bomber" and "Interception" and not 
Evasion.
Submarine Equipment provide an evasion bonus to submarines against ASW attacks (around 1.2),
Underway Replenishment
is a way to mitigate fuel penalties,
Arctic Camouflage (+ Arctic Equipment)
gives:
(non-stacking),
& Schnellboot Imp Pack
) are "very small and fast".
