The melee max hit formula
The game builds your max hit in two stages and rounds down at nearly every step. That rounding is why small bonuses often seem to vanish.
- Boost the level. Strength level plus your potion boost.
- Apply the combat boost. Multiply by the Strength boost from your Prayer level unlocks and round down.
- Add the style bonus. +3 on aggressive, +1 on controlled, nothing on accurate or defensive. Then add 8. This is your effective Strength.
- Void. A full melee void set multiplies effective Strength by 1.1, rounded down.
- Base max hit. 0.5 + effective Strength × (strength bonus + 64) ÷ 640, rounded down.
- Target bonuses. Multiply by the slayer helmet, salve, lance or obsidian bonus and round down again.
Worked example at 99 Strength
Unboosted, on aggressive, with +110 strength bonus: effective Strength is 99 + 3 + 8 = 110, and 0.5 + 110 × 174 ÷ 640 = 30.4. Max hit 30.
Now drink a super strength potion and switch on the level 70 melee boost. The potion adds 15% (rounded down) plus 5, taking 99 to 118. That boost multiplies it by 1.23 for 145. Add 3 and 8 for 156. Then 0.5 + 156 × 174 ÷ 640 = 42.9, a max hit of 42. On a slayer task with a black mask or slayer helmet it becomes 42 × 7/6 = 49.
The 42.9 is the useful part. One more point of strength bonus (+111) gives 43.2 and a max hit of 43. After that, each extra max hit needs about four more strength bonus at this effective level. The calculator shows that gap as "next max hit", so you can see whether an upgrade crosses a line or falls short of it.
Strength potions and combat boosts
| Potion | Boost | 99 Strength becomes |
|---|---|---|
| Strength potion | 10% + 3 | 111 |
| Super strength or super combat | 15% + 5 | 118 |
| Overload (+), raid only | 16% + 6 | 120 |
| Boost | Prayer level | Strength bonus |
|---|---|---|
| Level 4 Strength boost | 4 | 5% |
| Level 13 Strength boost | 13 | 10% |
| Level 31 Strength boost | 31 | 15% |
| Level 60 melee boost | 60 | 18% |
| Level 70 melee boost | 70 | 23% |
The potion is added before the boost multiplier, so the two compound. A stat restore potion keeps your Prayer points topped up on long trips, so the boost never drops.
Set effects and what stacks
- Black mask and slayer helmet: 7/6 damage (and accuracy) against your current slayer task only.
- Salve amulet: 7/6 against undead, or 1.2 for the (e) and (ei) versions. It does not stack with the slayer helmet bonus. Wear both and only the salve counts.
- Dragon hunter lance: +20% damage and accuracy against draconic monsters, and it does stack with the slayer helmet.
- Void melee: +10% to effective Strength and Attack, applied before the strength bonus step. It stacks with the others.
- Obsidian: the helmet, platebody and platelegs together give +10% with the TzHaar obsidian weapons, and a berserker necklace adds another 20% damage with those weapons.
Strength bonus or Strength levels?
Your max hit only changes at a breakpoint, and damage rolls between 0 and the max hit. So an upgrade that adds +4 strength bonus when you sit 5 short of the next hit adds nothing to your damage at all. Check the next-hit figure before you spend. At high levels, a few Strength levels often do the same job as an expensive item; the Strength training guide covers the fastest ways to get them.
Max hit is only half the picture, though. Accuracy and attack speed decide how often that number lands, so run the whole setup through the OSRS DPS calculator before buying anything big. For what to buy at each budget, see the melee gear guide. A black mask is one of the cheapest damage jumps in the game if you do Slayer.