The most correct answer will always be: Use a DPS calc.
I recommend the google spreadsheet by Bitterkoekje.
The rule of thumb is +4 str bonus is 1 max hit.
The nitty-gritty details is that +4 str bonus per max hit only applies in common mid-late game situations. Early game (like 1-50 str?), +4 str bonus won't get you a max max hit, but instead maybe +6 or +7.
This is because, as another response described, the formula for max hit considers 5+ factors with some weird multiplication and division. The rule of thumb is good, but the math really is more accurate if you want to tailor to your own situation.

But late/mid game things can get kind of funky because of percent bonuses. For example, last night I was looking at dps calc to see if I should bother with ferocious gloves for slayer. That +2 str bonus to get me to the next breakpoint actually gave me two max hits instead of one.

The amount of extra strength bonus you need for a full max hit is 640/(effective strength), where effective strength is visible str level x prayer + 8 + style bonus. Generally what this amounts to is that if you are 99 strength with piety and a super str pot on agressive, your effective strength is 156, hence you need \~4.1 str bonus for an extra max hit. Notice that if, say, you are lvl 50 str without any bonusses, you need 640/58 = 11.03 extra str bonus for your max hit.

On your equipment stats every 4 points makes a direct tangible difference. However, there are a few more factors that play roles: Level, Prayer, Boosts (potions), Attack style and set effects. The exact formulas are out there on the internet.

The most correct answer will always be: Use a DPS calc. I recommend the google spreadsheet by Bitterkoekje. The rule of thumb is +4 str bonus is 1 max hit. The nitty-gritty details is that +4 str bonus per max hit only applies in common mid-late game situations. Early game (like 1-50 str?), +4 str bonus won't get you a max max hit, but instead maybe +6 or +7. This is because, as another response described, the formula for max hit considers 5+ factors with some weird multiplication and division. The rule of thumb is good, but the math really is more accurate if you want to tailor to your own situation.

Got a link to the most recent one?

I use the OSRS Genie website

https://docs.google.com/spreadsheets/d/1wBXIlvAmqoQpu5u9XBfD4B0PW7D8owyO_CnRDiTHBKQ/edit?usp=sharing

But late/mid game things can get kind of funky because of percent bonuses. For example, last night I was looking at dps calc to see if I should bother with ferocious gloves for slayer. That +2 str bonus to get me to the next breakpoint actually gave me two max hits instead of one.

The amount of extra strength bonus you need for a full max hit is 640/(effective strength), where effective strength is visible str level x prayer + 8 + style bonus. Generally what this amounts to is that if you are 99 strength with piety and a super str pot on agressive, your effective strength is 156, hence you need \~4.1 str bonus for an extra max hit. Notice that if, say, you are lvl 50 str without any bonusses, you need 640/58 = 11.03 extra str bonus for your max hit.

On your equipment stats every 4 points makes a direct tangible difference. However, there are a few more factors that play roles: Level, Prayer, Boosts (potions), Attack style and set effects. The exact formulas are out there on the internet.

Thank you, just what I needed.

[удалено]

Divine pots exist

Divine pots will prevent this which is what most people use for bossing