OSRS DPS Calculator
Enter your levels, prayer, potion boost, gear bonuses and a target's defence to see your max hit, accuracy, DPS and expected time to kill for melee, ranged or magic.
Max hit
30
Accuracy
93.0%
Chance to deal non-zero damage
DPS
5.8
25.0 attacks/min
Attack roll
15,476
Hill giant defence roll
2,176
Time to kill (35 hp)
6.0s
~2.5 attacks
How it's calculated
Every combat calculator on this site runs through the same shared engine. First, an effective level:
effective level = floor(base level × (1 + prayer bonus %)) + combat-style bonus + 8
Then a max hit from the effective Strength (or Ranged Strength) level and gear strength bonus:
max hit = floor(0.5 + effective level × (gear strength bonus + 64) / 640)
And an attack roll (the same formula gives the target's defence roll, from their defence level and bonus):
attack roll = effective level × (gear attack bonus + 64)
Hit chance compares the two rolls -- when your attack roll is higher:
accuracy = 1 − (defence roll + 2) / (2 × (attack roll + 1))
DPS is accuracy times half your max hit (a hit is uniformly random between 0 and your max hit, so its average is half), divided by your weapon's attack speed in seconds (1 game tick = 0.6s). This is a community-documented OSRS combat formula, independently reverse-engineered and cross-verified across many separate theorycrafting sources for over a decade, implemented here from the formula itself.
Worked example
The calculator's own defaults: 80 Attack / 80 Strength, Piety active, a Super strength potion, the Aggressive combat style, an Abyssal whip, against a Hill giant (26 Defence, 35 hp).
| Boosted Strength level (potion) | 97 |
| Effective Strength level | 130 |
| Max hit | 30 |
| Attack roll vs. defence roll | 15,476 vs 2,176 |
| Accuracy | 93.0% |
| DPS / expected time to kill | 5.8 · 6.0s |
Plug the same inputs into the calculator above and it lands on the same result; that reconciliation is checked in the site's own test suite, not just written here.
Frequently Asked Questions
What formula does this DPS calculator actually run?
Effective level = floor(base level x prayer bonus) + combat-style bonus + 8, applied to the relevant stat. Max hit = floor(0.5 + effective Strength/Ranged-Strength level x (gear strength bonus + 64) / 640). Attack roll = effective Attack level x (gear attack bonus + 64), and the same formula gives the target's defence roll. Hit chance compares the two rolls; DPS is accuracy x (max hit / 2), divided by the weapon's attack speed in seconds. This is the standard, independently-documented OSRS combat formula -- see "How it's calculated" below for the full derivation.
Why does accuracy matter as much as max hit?
Max hit only caps your best-case damage -- accuracy decides how often you deal anything at all. A weapon with a huge max hit but low accuracy against a well-defended target can lose in real DPS to a faster, more accurate weapon with a smaller max hit, because DPS is accuracy x average damage, not max hit alone. That's why this calculator always shows both numbers, not just one.
Are the preset weapon and monster stats exact?
No -- they're a small, typed-from-memory convenience list of common gear and training targets, clearly approximate. Gear stats and monster defence values can change with game updates. For an exact result, use the custom gear option and type your own attack/strength bonus and the target's real defence level and bonus.
Why is magic handled differently from melee and ranged?
Melee and Ranged max hit both scale directly with a level (Strength or Ranged) through the same formula. Magic max hit is mostly fixed per spell or magic weapon, then scaled by a flat magic-damage percentage from gear -- it isn't derived from your Magic level the same way. Magic accuracy, on the other hand, does scale with effective Magic level through the same accuracy-roll formula as melee and ranged.
What does "time to kill" assume?
It's an expected value, not a guaranteed number: since each hit is 0 with probability (1 - accuracy) and otherwise uniformly random up to your max hit, the expected damage per attack is accuracy x (max hit / 2). Dividing the target's hitpoints by that gives the expected number of attacks, and multiplying by the weapon's attack speed gives expected real time. A specific kill will vary around this average.
Max Hit Calc is a set of fan-made calculators built from the game's published combat and experience formulas, not affiliated with, endorsed by, or operated on behalf of Jagex Ltd. Old School RuneScape is a trademark of Jagex Ltd. Any preset gear, monster or action values above are typed from general knowledge of the game and are approximate -- verify the current figure in-game before relying on it. See the Terms.