Improvement/Reference Charts
The tables below are the total bonus you get towards a particular stat when you have multiple equipment providing a bonus. The tables are based off the following optimised upgrade combinations:
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Equipment | 5/6 | 6/6 | 6/7 | 7/7 | 7/8 | 8/8 | 8/9 | 9/9 | 9/10 | 10/10 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Equipment | 7/7/7 | 7/7/8 | 7/8/8 | 8/8/8 | 8/8/9 | 8/9/9 | 9/9/9 | 9/9/10 | 9/10/10 | 10/10/10 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Equipment | 7/8/8/8 | 8/8/8/8 | 8/8/8/9 | 8/8/9/9 | 8/9/9/9 | 9/9/9/9 | 9/9/9/10 | 9/9/10/10 | 9/10/10/10 | 10/10/10/10 |
It is important to note that while whole number breakpoints are important, fractions should not be discounted as they can be multiplied by various formulas to hit the next whole number. Therefore, you should aim to maximise your available improvement bonus.
0.66 Modifier
Example: ASW 
from sonar and DC.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 0.66 | 0.94 | 1.15 | 1.33 | 1.49 | 1.63 | 1.76 | 1.88 | 2.00 | 2.10 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 3.12 | 3.26 | 3.39 | 3.52 | 3.64 | 3.77 | 3.88 | 4.00 | 4.10 | 4.21 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 5.29 | 5.41 | 5.53 | 5.65 | 5.77 | 5.88 | 6.00 | 6.10 | 6.21 | 6.32 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 7.42 | 7.54 | 7.65 | 7.77 | 7.88 | 8.00 | 8.10 | 8.21 | 8.32 | 8.43 |
0.7 Modifier
Example: Anti-Air 
from HA, MG, AAFD, and AA Radar.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 0.70 | 0.98 | 1.21 | 1.40 | 1.56 | 1.71 | 1.85 | 1.97 | 2.10 | 2.21 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 3.21 | 3.42 | 3.56 | 3.70 | 3.83 | 3.95 | 4.07 | 4.20 | 4.31 | 4.42 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 5.55 | 5.68 | 5.81 | 5.93 | 6.05 | 6.17 | 6.30 | 6.41 | 6.52 | 6.64 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 7.79 | 7.91 | 8.03 | 8.15 | 8.27 | 8.40 | 8.51 | 8.62 | 8.74 | 8.85 |
0.75 Modifier
Example: Firepower 
from sonar and DC.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 0.75 | 1.06 | 1.29 | 1.50 | 1.67 | 1.83 | 1.98 | 2.12 | 2.25 | 2.37 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 3.51 | 3.67 | 3.82 | 3.96 | 4.10 | 4.24 | 4.37 | 4.50 | 4.62 | 4.74 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 5.95 | 6.08 | 6.22 | 6.36 | 6.49 | 6.62 | 6.75 | 6.87 | 6.99 | 7.11 |
| Bonus | 8.34 | 8.48 | 8.61 | 8.74 | 8.87 | 9.00 | 9.12 | 9.24 | 9.36 | 9.48 |
1.0 Modifier
Example: Firepower from small and medium caliber guns. Shelling Accuracy 
from guns and anti-air radars.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 1.00 | 1.41 | 1.73 | 2.00 | 2.23 | 2.44 | 2.64 | 2.82 | 3.00 | 3.16 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 4.68 | 4.89 | 5.09 | 5.29 | 5.47 | 5.65 | 5.82 | 6.00 | 6.16 | 6.32 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 7.93 | 8.11 | 8.30 | 8.48 | 8.65 | 8.82 | 9.00 | 9.16 | 9.32 | 9.48 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 11.13 | 11.31 | 11.48 | 11.65 | 11.82 | 12.00 | 12.16 | 12.32 | 12.48 | 12.64 |
1.2 Modifier
Example: Torpedo power 
from machine guns.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Bonus | 1.20 | 1.69 | 2.07 | 2.40 | 2.68 | 2.93 | 3.17 | 3.39 | 3.60 | 3.79 | |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |
| Bonus | 5.62 | 5.87 | 6.11 | 6.34 | 6.56 | 6.78 | 6.99 | 7.20 | 7.39 | 7.58 | |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
| Bonus | 9.52 | 9.74 | 9.96 | 10.18 | 10.38 | 10.59 | 10.80 | 10.99 | 11.18 | 11.38 | |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | |
| Bonus | 13.35 | 13.57 | 13.78 | 13.98 | 14.19 | 14.40 | 14.59 | 14.78 | 14.98 | 15.17 |
1.25 Modifier
Example: Line of Sight Template:LoS from RADAR.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 1.25 | 1.76 | 2.16 | 2.50 | 2.79 | 3.06 | 3.30 | 3.53 | 3.75 | 3.95 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 5.85 | 6.12 | 6.36 | 6.61 | 6.84 | 7.07 | 7.28 | 7.50 | 7.70 | 7.90 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 9.92 | 10.14 | 10.37 | 10.60 | 10.82 | 11.03 | 11.25 | 11.45 | 11.65 | 11.85 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 13.91 | 14.14 | 14.35 | 14.57 | 14.78 | 15.00 | 15.20 | 15.40 | 15.60 | 15.81 |
1.3 Modifier
Example: ASW Accuracy from sonars.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 1.30 | 1.83 | 2.25 | 2.60 | 2.90 | 3.18 | 3.43 | 3.67 | 3.90 | 4.11 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 6.09 | 6.36 | 6.62 | 6.87 | 7.11 | 7.35 | 7.57 | 7.80 | 8.01 | 8.22 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 10.31 | 10.55 | 10.79 | 11.03 | 11.25 | 11.47 | 11.70 | 11.991 | 12.12 | 12.33 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 14.47 | 14.70 | 14.93 | 15.15 | 15.37 | 15.60 | 15.81 | 16.02 | 16.23 | 16.44 |
1.5 Modifier
Example: Firepower from large caliber main guns. Torpedo evasion 
from sonars.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 1.50 | 2.12 | 2.59 | 3.00 | 3.35 | 3.67 | 3.96 | 4.24 | 4.50 | 4.74 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 7.02 | 7.34 | 7.64 | 7.93 | 8.21 | 8.48 | 8.74 | 9.00 | 9.24 | 9.48 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 11.90 | 12.17 | 12.45 | 12.72 | 12.98 | 13.24 | 13.50 | 13.74 | 13.98 | 14.23 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 16.69 | 16.97 | 17.22 | 17.48 | 17.74 | 18.00 | 18.24 | 18.48 | 18.73 | 18.97 |
2.0 Modifier
Example: Torpedo accuracy from anti-air guns and torpedoes.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 2.00 | 2.82 | 3.46 | 4.00 | 4.47 | 4.89 | 5.29 | 5.65 | 6.00 | 6.32 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 9.37 | 9.79 | 10.19 | 10.58 | 10.94 | 11.31 | 11.65 | 12.00 | 12.32 | 12.64 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 15.87 | 16.23 | 16.60 | 16.97 | 17.31 | 17.65 | 18.00 | 18.32 | 18.64 | 18.97 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 22.26 | 22.62 | 22.97 | 23.31 | 23.65 | 24.00 | 24.32 | 24.64 | 24.97 | 25.29 |
3.0 Modifier
Example: Fleet Anti-Air from high angle guns.
| Total ★ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Bonus | 3.00 | 4.24 | 5.19 | 6.00 | 6.70 | 7.34 | 7.93 | 8.48 | 9.00 | 9.48 |
| Total ★ | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Bonus | 14.05 | 14.69 | 15.28 | 15.87 | 16.42 | 16.97 | 17.48 | 18.00 | 18.48 | 18.97 |
| Total ★ | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bonus | 23.81 | 24.35 | 24.90 | 25.45 | 25.97 | 26.48 | 27.00 | 27.48 | 27.97 | 28.46 |
| Total ★ | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| Bonus | 33.39 | 33.94 | 34.45 | 34.97 | 35.48 | 36.00 | 36.48 | 36.97 | 37.46 | 37.94 |
1.0+1.5 Modifier
Bonus Firepower for Battleships with 2 main guns and 1 AP. Highlights indicate threshold changes.
| Total Main Gun ★ | AP Shell ★ | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Gun 1 | Gun 2 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 1 | 1 | 4.000 | 4.414 | 4.732 | 5.000 | 5.236 | 5.449 | 5.646 | 5.828 | 6.000 | 6.162 |
| 2 | 1 | 4.621 | 5.036 | 5.353 | 5.621 | 5.857 | 6.071 | 6.267 | 6.450 | 6.621 | 6.784 |
| 3 | 1 | 5.098 | 5.512 | 5.830 | 6.098 | 6.334 | 6.548 | 6.744 | 6.927 | 7.098 | 7.260 |
| 2 | 2 | 5.243 | 5.657 | 5.975 | 6.243 | 6.479 | 6.692 | 6.888 | 7.071 | 7.243 | 7.405 |
| 4 | 1 | 5.500 | 5.914 | 6.232 | 6.500 | 6.736 | 6.949 | 7.146 | 7.328 | 7.500 | 7.662 |
| 3 | 2 | 5.719 | 6.134 | 6.451 | 6.719 | 6.955 | 7.169 | 7.365 | 7.548 | 7.719 | 7.882 |
| 5 | 1 | 5.854 | 6.268 | 6.586 | 6.854 | 7.090 | 7.304 | 7.500 | 7.683 | 7.854 | 8.016 |
| 4 | 2 | 6.121 | 6.536 | 6.853 | 7.121 | 7.357 | 7.571 | 7.767 | 7.950 | 8.121 | 8.284 |
| 6 | 1 | 6.174 | 6.588 | 6.906 | 7.174 | 7.410 | 7.624 | 7.820 | 8.003 | 8.174 | 8.337 |
| 3 | 3 | 6.196 | 6.610 | 6.928 | 7.196 | 7.432 | 7.646 | 7.842 | 8.025 | 8.196 | 8.358 |
| 7 | 1 | 6.469 | 6.883 | 7.201 | 7.469 | 7.705 | 7.918 | 8.114 | 8.297 | 8.469 | 8.631 |
| 5 | 2 | 6.475 | 6.890 | 7.207 | 7.475 | 7.711 | 7.925 | 8.121 | 8.304 | 8.475 | 8.638 |
| 4 | 3 | 6.598 | 7.012 | 7.330 | 7.598 | 7.834 | 8.048 | 8.244 | 8.427 | 8.598 | 8.760 |
| 8 | 1 | 6.743 | 7.157 | 7.475 | 7.743 | 7.979 | 8.192 | 8.388 | 8.571 | 8.743 | 8.905 |
| 6 | 2 | 6.796 | 7.210 | 7.528 | 7.796 | 8.032 | 8.245 | 8.441 | 8.624 | 8.796 | 8.958 |
| 5 | 3 | 6.952 | 7.366 | 7.684 | 7.952 | 8.188 | 8.402 | 8.598 | 8.781 | 8.952 | 9.114 |
| 9 | 1 | '7.000' | 7.414 | 7.732 | '8.000' | 8.236 | 8.449 | 8.646 | 8.828 | 9.000 | 9.162 |
| 4 | 4 | '7.000' | 7.414 | 7.732 | '8.000' | 8.236 | 8.449 | 8.646 | 8.828 | 9.000 | 9.162 |
| 7 | 2 | 7.090 | 7.504 | 7.822 | 8.090 | 8.326 | 8.539 | 8.736 | 8.918 | 9.090 | 9.252 |
| 10 | 1 | 7.243 | 7.658 | 7.975 | 8.243 | 8.479 | 8.693 | 8.889 | 9.072 | 9.243 | 9.406 |
| 6 | 3 | 7.272 | 7.687 | 8.004 | 8.272 | 8.508 | 8.722 | 8.918 | 9.101 | 9.272 | 9.435 |
| 5 | 4 | 7.354 | 7.768 | 8.086 | 8.354 | 8.590 | 8.804 | 9.000 | 9.183 | 9.354 | 9.516 |
| 8 | 2 | 7.364 | 7.778 | 8.096 | 8.364 | 8.600 | 8.813 | 9.010 | 9.192 | 9.364 | 9.526 |
| 7 | 3 | 7.567 | 7.981 | 8.299 | 8.567 | 8.803 | 9.016 | 9.212 | 9.395 | 9.567 | 9.729 |
| 9 | 2 | 7.621 | 8.036 | 8.353 | 8.621 | 8.857 | 9.071 | 9.267 | 9.450 | 9.621 | 9.784 |
| 6 | 4 | 7.674 | 8.088 | 8.406 | 8.674 | 8.910 | 9.124 | 9.320 | 9.503 | 9.674 | 9.837 |
| 5 | 5 | 7.708 | 8.122 | 8.440 | 8.708 | 8.944 | 9.158 | 9.354 | 9.537 | 9.708 | 9.870 |
| 8 | 3 | 7.841 | 8.255 | 8.573 | 8.841 | 9.077 | 9.290 | 9.486 | 9.669 | 9.841 | 10.003 |
| 10 | 2 | 7.865 | 8.279 | 8.597 | 8.865 | 9.101 | 9.314 | 9.510 | 9.693 | 9.865 | 10.027 |
| 7 | 4 | 7.969 | 8.383 | 8.701 | 8.969 | 9.205 | 9.418 | 9.614 | 9.797 | 9.969 | 10.131 |
| 6 | 5 | 8.028 | 8.443 | 8.760 | 9.028 | 9.264 | 9.478 | 9.674 | 9.857 | 10.028 | 10.191 |
| 9 | 3 | 8.098 | 8.512 | 8.830 | 9.098 | 9.334 | 9.548 | 9.744 | 9.927 | 10.098 | 10.260 |
| 8 | 4 | 8.243 | 8.657 | 8.975 | 9.243 | 9.479 | 9.692 | 9.888 | 10.071 | 10.243 | 10.405 |
| 7 | 5 | 8.323 | 8.737 | 9.055 | 9.323 | 9.559 | 9.772 | 9.968 | 10.151 | 10.323 | 10.485 |
| 10 | 3 | 8.341 | 8.756 | 9.074 | 9.341 | 9.578 | 9.791 | 9.987 | 10.170 | 10.341 | 10.504 |
| 6 | 6 | 8.348 | 8.763 | 9.081 | 9.348 | 9.585 | 9.798 | 9.994 | 10.177 | 10.348 | 10.511 |
| 9 | 4 | 8.500 | 8.914 | 9.232 | 9.500 | 9.736 | 9.949 | 10.146 | 10.328 | 10.500 | 10.662 |
| 8 | 5 | 8.597 | 9.011 | 9.329 | 9.597 | 9.833 | 10.046 | 10.242 | 10.425 | 10.597 | 10.759 |
| 7 | 6 | 8.643 | 9.057 | 9.375 | 9.643 | 9.879 | 10.092 | 10.289 | 10.471 | 10.643 | 10.805 |
| 10 | 4 | 8.743 | 9.158 | 9.475 | 9.743 | 9.979 | 10.193 | 10.389 | 10.572 | 10.743 | 10.906 |
| 9 | 5 | 8.854 | 9.268 | 9.586 | 9.854 | 10.090 | 10.304 | 10.500 | 10.683 | 10.854 | 11.016 |
| 8 | 6 | 8.917 | 9.331 | 9.649 | 9.917 | 10.153 | 10.366 | 10.563 | 10.745 | 10.917 | 11.079 |
| 7 | 7 | 8.937 | 9.351 | 9.669 | 9.937 | 10.173 | 10.387 | 10.583 | 10.766 | 10.937 | 11.100 |
| 10 | 5 | 9.098 | 9.512 | 9.830 | 10.098 | 10.334 | 10.547 | 10.743 | 10.926 | 11.098 | 11.260 |
| 9 | 6 | 9.174 | 9.588 | 9.906 | 10.174 | 10.410 | 10.624 | 10.820 | 11.003 | 11.174 | 11.337 |
| 8 | 7 | 9.211 | 9.625 | 9.943 | 10.211 | 10.447 | 10.661 | 10.857 | 11.040 | 11.211 | 11.374 |
| 10 | 6 | 9.418 | 9.832 | 10.150 | 10.418 | 10.654 | 10.867 | 11.063 | 11.246 | 11.418 | 11.580 |
| 9 | 7 | 9.469 | 9.883 | 10.201 | 10.469 | 10.705 | 10.918 | 11.114 | 11.297 | 11.469 | 11.631 |
| 8 | 8 | 9.485 | 9.899 | 10.217 | 10.485 | 10.721 | 10.935 | 11.131 | 11.314 | 11.485 | 11.648 |
| 10 | 7 | 9.712 | 10.126 | 10.444 | 10.712 | 10.948 | 11.162 | 11.358 | 11.540 | 11.712 | 11.874 |
| 9 | 8 | 9.743 | 10.157 | 10.475 | 10.743 | 10.979 | 11.192 | 11.388 | 11.571 | 11.743 | 11.905 |
| 10 | 8 | 9.986 | 10.400 | 10.718 | 10.986 | 11.222 | 11.436 | 11.632 | 11.814 | 11.986 | 12.148 |
| 9 | 9 | 10.000 | 10.414 | 10.732 | 11.000 | 11.236 | 11.449 | 11.646 | 11.828 | 12.000 | 12.162 |
| 10 | 9 | 10.243 | 10.658 | 10.975 | 11.243 | 11.479 | 11.693 | 11.889 | 12.072 | 12.243 | 12.406 |
| 10 | 10 | 10.487 | 10.901 | 11.219 | 11.487 | 11.723 | 11.936 | 12.133 | 12.315 | 12.487 | 12.649 |