About Max Hit Calc

Max Hit Calc is run by a single independent builder as eight Old School RuneScape (OSRS) calculators built around one idea: show the formula, not just the number. Every tool states the game mechanic it runs, works a real example through to the number, and marks every preset value clearly as approximate rather than presenting it as an exact, always-current figure.

How the calculators work

The combat calculators (DPS, Max Hit, and the accuracy portion of both) run through one shared effective-level and accuracy-roll engine, rather than each tool re-implementing its own version of the formula. The Combat Level, XP, Skill Training, Construction and Prayer calculators share the same XP-table and actions-needed engine. Every formula is checked against a hand-derived expected value in the site's own test suite before it ships.

Where the formulas come from

The effective-level, max-hit, accuracy-roll and combat-level formulas are community-documented OSRS game mechanics: independently reverse-engineered and published, then cross-verified, across many separate theorycrafting sources over more than a decade. The XP-table formula is the game's own published experience-curve design, computed here from the formula itself rather than a copied 1-99 table. None of this is scraped from the OSRS Wiki or any other database -- see each calculator's "how it's calculated" section for the exact formula.

Preset values

A handful of calculators offer a small preset list -- common weapons, monsters, spells, skilling actions, bones and altars -- typed from general public knowledge of the game's long-stable stat values, purely as a convenience. These are not pulled from a live database and are not guaranteed current; every preset is labelled approximate, and every calculator also accepts a fully custom, typed-in value for an exact result. Verify any number that matters against the game itself before relying on it.

What it doesn't do

Max Hit Calc is not affiliated with, endorsed by, or operated on behalf of Jagex Ltd. Old School RuneScape is a trademark of Jagex Ltd. Every result here is an estimate from the inputs you enter and the formulas above -- real in-game outcomes involve randomness, exact current item stats, and mechanics this tool can't always capture. See Terms.

Every calculator

• OSRS DPS Calculator -- Calculate melee, ranged or magic DPS in Old School RuneScape from your levels, prayer, gear bonuses and target's defence, with max hit, accuracy and expected time to kill shown.
• Max Hit Calculator -- Calculate your maximum hit for melee, ranged or magic in OSRS from your level, prayer bonus, potion boost and gear strength bonus, with the formula and a worked example shown.
• Combat Level Calculator -- Calculate your OSRS combat level from Attack, Strength, Defence, Hitpoints, Prayer, Ranged and Magic, with the full base/melee/ranged/magic breakdown and levels needed for your next combat level.
• OSRS XP Calculator -- Convert between OSRS level and experience using the game's own XP-table formula, see XP needed to a target level, and turn an XP-per-hour rate into a real time-to-level estimate.
• Skill Training Calculator -- Plan OSRS skill training: pick a skill and a training method, enter your current XP and target level, and see how many actions it takes -- Woodcutting, Fishing, Mining and Firemaking presets included.
• Construction Calculator -- Calculate planks and build actions needed for a target Construction level in OSRS, using a small preset list of common training methods, with total plank cost shown.
• Drop Rate / Dry Calculator -- Calculate your OSRS drop-rate odds: chance of still being dry after N kills, and how many kills you need for a 50%, 90% or custom cumulative chance at a drop.
• Prayer Calculator -- Calculate OSRS Prayer XP from bones or ensouled heads with altar multipliers, and how many bones you need for a target Prayer level.

Corrections

If a formula or preset value here is wrong or out of date, email hello@maxhitcalc.com.