OSRS Dry Calculator 2025 - Old School RuneScape Drop Rate Calculator

OSRS Drop Rate Calculator

Calculate your dry streak probability and drop rate statistics

Manual Input

Drop Rate (1 in X)

Enter the denominator (e.g., 128 for 1/128 drop rate)

Number of Kills/Attempts

Item/Drop Name (Optional)

Quick Tips

• Enter only the number after 1/ (e.g., 128 for 1/128)
• Each kill/attempt is independent
• Probability doesn't change based on previous results
• Use preset bosses for accurate rates

Popular OSRS Bosses & Drops

Theatre of Blood

Scythe of Vitur (1/5000)

Chambers of Xeric

Twisted Bow (1/3000)

Lizardman Shaman

Dragon Warhammer (1/5000)

Zulrah

Any Unique (1/512)

Vorkath

Any Unique (1/128)

Corporeal Beast

Elysian Sigil (1/1000)

General Graardor

Bandos Chestplate (1/256)

Kree'arra

Armadyl Crossbow (1/508)

Drop Probability Results

Chance of Getting Drop

0%

Probability of at least 1 drop

Chance of Going Dry

0%

Probability of 0 drops

Expected Drops

0.0

Average number of drops

Detailed Statistics

Drop Information

Drop Rate: 1/0

Kill Count: 0

Drop Rate %: 0%

Luck Assessment

Calculate to see assessment

Enter your drop rate and kill count to get started

Probability Breakdown

OSRS Drop Rate Reference

Popular Bosses

Zulrah (Any Unique): 1/512

Vorkath (Any Unique): 1/128

Bandos (BCP): 1/256

Armadyl (ACB): 1/508

Sara (ACB): 1/508

Raids & End Game

CoX (T-Bow): 1/3,000

ToB (Scythe): 1/5,000

Corp (Ely): 1/1,000

Nightmare (Inq Pieces): 1/1,000

ToA (Purple): Variable

Slayer & Others

Lizardman (DWH): 1/5,000

Cerberus (Crystal): 1/512

Kraken (Trident): 1/512

Abyssal Demon (Whip): 1/512

Basilisk Knight (Jaw): 1/5,000

Understanding OSRS Probabilities

How Drop Rates Work

• Each kill/attempt is independent - previous results don't affect future drops

• A 1/128 drop rate means 1 in 128 chance per kill, not guaranteed in 128 kills

• You have a ~63% chance of getting the drop within the drop rate number of kills

• Going 2x the drop rate dry has about a 13.5% chance of happening

• Extremely rare drops (1/5000+) often require thousands of attempts

Luck Categories

Lucky (Under 50% of drop rate)

You got the drop faster than average

Average (50% - 200% of drop rate)

Normal luck, most players fall here

Unlucky (200%+ of drop rate)

Going dry - happens to about 13.5% of players

Frequently Asked Questions

What is a dry streak in OSRS?

A dry streak in OSRS refers to a period of kills or attempts without receiving a specific rare drop. For example, going 500 kills at a boss without getting the desired rare item when the drop rate is 1/100.

How do OSRS drop rates work?

OSRS drop rates are expressed as fractions (e.g., 1/128 means 1 in 128 chance per kill). Each kill is independent, so previous kills don't affect future drop chances. The dry calculator helps determine the probability of going dry for a certain number of kills.

What is considered unlucky in OSRS?

Generally, going 2-3 times the drop rate without receiving an item is considered unlucky. For a 1/100 drop rate, going 200-300 kills dry would be unlucky, and anything beyond 400+ kills would be extremely unlucky.

How accurate is the OSRS dry calculator?

The dry calculator uses mathematical probability formulas and official OSRS drop rates to provide accurate statistics. It calculates the exact probability of going dry for any number of kills using binomial distribution.

Can the dry calculator predict when I'll get a drop?

No, the calculator cannot predict future drops as each kill is independent. It only calculates the probability of certain outcomes based on mathematical statistics and historical drop rates.