XP Calcs
Tombs of Amascut (ToA) raid ledger

OSRS ToA Calculator

Explore how Tombs of Amascut (ToA) raid level and personal contribution change a transparent planning probability, then compound it across a target number of raids.

Set activity assumptions

Estimated unique chance

3.50%

50.96% chance across 20 raids; about 11.7 hours at the entered pace.

How it works

The Tombs of Amascut (ToA) reward system uses encounter points, team performance, deaths, raid level and eligibility rules. This deliberately simplified curve is useful for scenario comparison but is not a reconstruction of the complete loot-roll algorithm. Treat the contribution input as your fraction of the modeled team chance.

pscenario=min⁡(55%, (2%+max⁡(0, raid level−150)×0.01%)×contribution)p_{\text{scenario}} = \min\left( 55\%,\ \left( 2\% + \max(0,\ \text{raid level} - 150) \times 0.01\% \right) \times \text{contribution} \right)
Inputs are kept at full precision. Discrete counts round up when a partial action cannot complete the goal; probabilities and rates keep their fractional meaning.

Worked example

At Tombs of Amascut (ToA) raid level 300 and full personal contribution, the scenario rate is 3.5% per raid. Independent compounding across multiple completions uses 1 − (1 − p)ⁿ.

Interpreting the result

Start by checking that each field describes the same scenario as the result: levels are visible base levels, bonuses are entered separately, costs are per unit, and a one-in-X rate means one divided by X on each eligible roll. The calculator updates immediately and writes the complete input state into the address bar. “Copy link” preserves those assumptions; “Copy result” copies a short summary rather than the entire method.

Do not treat a rounded count as an hourly rate. A required-action total says how many successful units complete the target under the entered reward. Banking, movement, failed attempts, animation timing, missed ticks and setup changes affect elapsed time. When time matters, measure a representative session with the same method and divide the required count by the observed successful actions per hour.

Economic outputs are arithmetic scenarios rather than live market quotations. Check current item values before buying supplies, include any outputs that can be sold, and consider limits or low-volume price movement. Probability outputs describe repeated independent trials; they do not promise that a result arrives at the displayed attempt count. The visible formula is the authority for what this page includes.

Read this as a planning estimate. Game updates, equipment effects, failures, travel, downtime and live prices can move a real session away from the mathematical result. Check the inputs against the account and use the output as a reproducible baseline.

Questions about OSRS ToA Calculator

Is this the exact purple chance?
No. It is explicitly a simplified scenario curve; real personal points and raid rules determine the roll.
What should contribution be for solo?
Use 1 for the model's full personal contribution.
Does a death matter?
The simplified input does not model deaths directly; reduce contribution to explore a lower effective share.

Sources

Mechanics and fixed tables were reviewed in 2026. Price-like inputs are user-controlled or approximate rather than live quotes. Source links name the public reference used for the page; the visible formula states the exact implementation.

  1. Old School RuneScape Wiki — Experience — Public XP table and level formula, reviewed 2026.
  2. Old School RuneScape Wiki — Combat level — Seven-stat combat-level formula, reviewed 2026.
  3. Old School RuneScape Wiki — Maximum melee hit — Effective Strength and maximum-hit formula, reviewed 2026.
  4. Old School RuneScape Wiki — Attack roll — Accuracy and defence-roll mechanics, reviewed 2026.
  5. Old School RuneScape Wiki — Calculators — Public skill, activity and reward tables, reviewed 2026.

Related calculators

Dry calculatorIndependent drop-style chance methods share the same interpretation model.Slayer task calculatorCompare weighted task assignments with raid-style chance work.Combat path calculatorPlan combat goals before entering long scenario sessions.

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