HP mystery

I'm pretty sure this is correct, but I haven't A:B tested to be sure.

This has the effect of making the "ship HP" multipliers extra-effective, since they take into account equipped items as well.

Note that your Big Shield's HP is subtotaled first (so the item-specific perks and talents are applied there) and then the result is added to Ship HP.

In a formula, it would be:

(Ship Base HP + Ship Talent HP + Ship Perk HP + ((Item Base HP + Item Perk/Talent HP) * Item Multiplier)) * Ship HP Multiplier

You can also check your Big Shield by tapping its HP to see how much of that is derived from perks/talents vs base score as well.

 

Not quite. The individual multipliers are added before being applied as one - so you'll need to tap on the shield's HP itself to see what they are. I'm assuming right now you're probably at (+50 HP, +35% Big Shield) based on your level, so working backwards, the item itself it would be about 705HP base. Add 150HP per Epic HP perk, 50HP from your talents, and the 35% multiplier, you get:

(705 + 450 + 50) * 1.35 = 1626

If you get another 5% to all shields, the multiplier becomes 1.4 and you should end up with

(705 + 450 + 50) * 1.4 = 1687

Now that you've calculated out the item, you can add it into the "total Ship HP" equation, bringing your the total to

(1750 + 400 + 1687) * 1.08 = 4143 (might get rounded to 4144)

If you get the "3% more Speeder HP" talent as well, that then becomes

(1750 + 400 + 1687) * 1.08 = 4259

Seems like I need to make a quick calculator for this.

 

Not quite. You have to calculate the items individually first, then the result is part of the Ship HP.

I'll break it down using myself as an example.

The Ship:


The Shield:


The formula:
(Ship Base HP + Ship Talent HP + Ship Perk HP + ((Item Base HP + Item Perk/Talent HP) * Item Multiplier)) * Ship HP Multiplier

So for my Mk5 Fixer, we get:

(2130 + 200 + 0 + ((365 + 350 + 125) * 1.3)) * 1.2
(2330 + (840 * 1.3)) * 1.2
(2330 + 1092) * 1.2
3422 * 1.2
4106HP

Note that because of how this is calculated, the "item multiplier" for Shields are effectively increased by the "ship multiplier" - it effectively gets +56% rather than +50% in this case. As @Kitterini mentioned here, Defenders have an even higher potential "ship multiplier" of +58% - if they have maxed Shield "item multipliers" of 35% for small and 50% for Big, that makes every additional 100 base HP on a Standard Shield worth 213 ship HP, and each on a Big Shield worth 237 ship HP.

Clear as mud, right?

 

Correct, the formula is for total effective HP once the shield is attached to a ship. Even though my shield only shows as being worth 1092HP, when I equip it I get 1310HP more because it's added to the base HP before the 20% ship bonus is counted.

Unfortunately the complicated math is necessary, because if I just added up the numbers that way, it would be
(2130 + 200 + 365 + 350 + 125) * 1.5
Which gives a total of 4755HP - while I'd appreciate the extra health, it's not accurate.

@Jasper21 has it nailed.

 

That's exactly the same math I did, I just expanded it out more to show all of the detail and the extra multipliers that can be leveraged best. As Jasper pointed out:

It's important to understand how that +100HP is worth more than its face value, and also how that value changes depending on your talent choices and even the ship used.