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About the OSRS Raid Calculators
Work out your purple chance in the Tombs of Amascut, the Chambers of Xeric and the Theatre of Blood from the OSRS Wiki formulas, with the GE value of each unique and your expected unique value per raid.
How to use the OSRS Raid Calculators
- Pick ToA, CoX or ToB.
- ToA: enter the raid level, party size and your reward points, plus the party total if scores differ.
- CoX: enter the team points and, optionally, your own. Tick Challenge Mode if it applies.
- ToB: enter the team size and deaths, plus your deaths and MVP points if you have them. Tick Hard Mode if it applies.
How the numbers are worked out
- ToA: 1% purple chance per (10,500 - 20 × scaled raid level) points after removing the 5,000 starting points, using the whole party's points, capped at 55%, and shared by points.
- CoX: 1% per 8,676 team points, capped at 65.7% per roll (570,000 points); points above that roll again, up to six purples per raid.
- ToB: 1/9.1 for the whole team with no deaths (1/7.7 in Hard Mode), for any team size. Deaths lower it.
- Unique weights: CoX /60 in normal mode and /56 in Challenge Mode (since 12 August 2026). Above raid level 300 the ToA fang and Lightbearer get rarer and the other uniques more common. Below raid level 150 some ToA purples need an extra 1/50 roll.
- Unique value uses live GE prices. Common loot is not priced.
Frequently asked questions
How is the ToA purple chance calculated?
1% for every 10,500 - 20 × scaled raid level points, after the 5,000 starting points are removed, using the whole party's points. It is capped at 55%, and the purple goes to one player in proportion to their points.
How many points for a CoX purple?
Each 8,676 team points gives a 1% chance, up to 65.7% at 570,000 points. Points above that roll for another purple, up to six per raid.
What is the ToB purple rate?
1/9.1 for the whole team with no deaths, whatever the team size, and 1/7.7 in Hard Mode. Deaths lower it, and the MVP is most likely to get the item.
Does the ToA chance include deaths?
Enter the points you actually ended with. Death penalties are already taken out of those points.
Does the calculator price common loot?
No. It values the unique table at live GE prices; common chest loot is not included.
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