Currently, there are three known purposes for Line of Sight (LoS):

  • Increasing success rate in the detection phase, which allows participation in aerial combat.
  • A higher Fleet total LoS (FLoS, or known as Simple LoS) positively correlates with the trigger chance of artillery spotting for a ship's double/cut-in attack in day battle.
    • Fleet total LoS is simply the summation of all LoS stats from your ships, including bonuses from the equipment.
  • Effective LoS (eLoS), which allows the fleet to reach a specific node (usually a pre-boss or boss node) instead of being diverted to a dead end.
    • Effective LoS has been employed in many Event Maps since Spring 2014 Event, Extra Operation Maps (including 1-6, 2-5, 3-5, 4-5), and some World 6 Maps.
    • There are special formulas being used to calculate eLoS. As a general consensus, LoS bonuses from equipment (especially reconnaissance seaplanes) are more important than an individual ship's LoS stats.
    • See sections below for the currently established formula on how to calculate eLoS.
  • Reconnaissance Seaplane equipped on a light cruiser with no plane slots can contribute to LoS.[1] But if it is equipped onto ships and then shot down, it cannot contribute to LoS check performed afterward.

Effective Line of Sight calculation method

2-5 old formula

To avoid confusion, content here is archived into a sub-page which only serves as a reference. Note that the values obtained from the 2-5 old formula are not compatible with those from 2-5 new/fall formula nor the simplified formula.

2-5 fall formula

With the advent of the 2014 Fall Event, a new formula for Effective LoS has been devised to account for inconsistencies of the old formula. [2][3]

Also known as 2-5 autumn formula, 2-5 new formula or new eLoS formula in some places. It is also the eLoS formula or the LoS formula as it has already become a de-facto standard on how to calculate (e)los.

  • Effective LoS = Dive Bomber LoS x (1.04) + Torpedo Bomber LoS x (1.37) + Carrier-based Reconnaissance Plane LoS x (1.66) + Reconnaissance Seaplane LoS x (2.00) + Seaplane Bomber LoS x (1.78) + Small Radar LoS x (1.00) + Large Radar LoS x (0.99) + Searchlight LoS x (0.91) + √(base LoS of each ship) x (1.69) + (HQ level rounded up to the next multiple of 5) x (-0.61)
  • √(base LoS of each ship) x (1.69) = Calculate the square root of each ship's LoS (base value without any equipment) separately, then add the values together and multiply by 1.69
  • Regarding the HQ Level: For example, if your HQ level is 101~105, use 105. If it's 106~110, use 110. And so on.

Excel file that calculates the fleet's LoS for you: (courtesy of Kouma231)

new fall simplified

It is a tidy up version of 2-5 fall formula. Click this link for details.

Unknown Factors in 2-5 Fall/NFS Formula calculation

Currently, how the 2-5 fall formula would be affected by Fighters, FCF, SCAMP, ASW Liason Aircraft, Improvement, and Aircraft Proficiency are still undetermined. Some calculators assume equipment in the list have 1.00x of their los value influence on the 2-5 fall value.

Formula 33

Requires further testing. Similar to the New Fall Simplified formula, but reportedly more accurate. Using this model, a value of 31 eLoS would guarantee failing the 2-5 LoS check, while a value of 33 eLoS would succeed 100% of the time. It is described as follows[4]:

  • is the equipment multiplier:
    • Carrier-Based Fighter: 0.6
    • Carrier-Based Dive Bomber: 0.6
    • Carrier-Based Torpedo Bomber: 0.8
    • Carrier-Based Reconnaissance Aircraft: 1
    • Reconnaissance Seaplane: 1.2
    • Seaplane Bomber: 1.1
    • Small Radar: 0.6
    • Large Radar: 0.6
    • ASW Patrol Aircraft: 0.6
    • Searchlight (Small and Large): 0.6
    • Fleet Command Facility: 0.6
    • SCAMP: 0.6
    • Skilled Lookouts: 0.6
    • Sonar: 0.6
    • Large Flying Boat: 0.6
    • Seaplane Fighter: 0.6
  • is the displayed LoS value of the equipment
  • is the equipment's improvement bonus to eLoS
    • This is calculated by multiplying , the improvement multiplier of that equipment, with the square root of the equipment's improvement level.
      • The improvement multiplier of all Radars is 1.25, Reconnaissance Seaplanes is 1.2, and Searchlight is 0 (that is, it receives no eLoS bonus when improved)
  • is the ship's base LoS
  • is the HQ level. The ceil operation means that the value is rounded up every 2.5 HQ levels.
  • is an additional variable representing the number of empty ship slots in your fleet. For instance, if your fleet contains only 2 ships, would be 4 and thus would yield 8.
    • It is unknown whether this value increases mid-sortie if a ship disappears from your fleet (e.g. sinking).

Special Notice to users of KCV v.4.2.5 as well as older version of some other software

  • Please update your software to a more recent version which patched a calculation mistake.


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