Osrs Attack Calculator

Calculate Your OSRS Attack Effectiveness

Enter your combat stats and target’s defense to estimate your hit chance and damage per second (DPS).

What is an OSRS Attack Calculator?

An OSRS Attack Calculator is an essential tool for players of Old School RuneScape looking to optimize their combat performance. It helps you estimate your chances of hitting an opponent and the average damage you can expect to deal per second (DPS) based on your current stats, gear, prayers, potions, and your target’s defensive capabilities. This calculator provides a data-driven approach to understanding and improving your combat effectiveness.

Who should use it?

• PvMers (Player vs. Monster): To determine the most efficient gear and setup for bossing, slayer tasks, or general monster grinding.
• PvPers (Player vs. Player): To understand their offensive potential against different opponent setups.
• Trainers: To identify optimal training methods and gear progression for faster experience gains.
• Theorycrafters: For those who enjoy delving into the mechanics of OSRS combat and testing different scenarios.

Common Misconceptions:

• It’s a guarantee: The OSRS Attack Calculator provides averages and probabilities. Actual combat involves randomness, so results are estimates, not certainties.
• It includes special attacks: Most basic attack calculators, including this one, do not account for the unique mechanics and damage multipliers of special attacks.
• It calculates Max Hit: While crucial for DPS, Max Hit is primarily determined by your Strength level and strength-boosting gear, not Attack. This calculator uses your provided Max Hit to calculate DPS. For a dedicated tool, see our OSRS Max Hit Calculator.

OSRS Attack Calculator Formula and Mathematical Explanation

Understanding the underlying formulas of the OSRS Attack Calculator is key to mastering combat. The calculation involves several steps to determine your effective attack level, compare it against the enemy’s defense, and ultimately estimate your hit chance and DPS.

Step-by-step Derivation:

1. Calculate Potion Bonus:
   • Attack Potion: +3
   • Super Attack Potion: floor(Attack Level * 0.15) + 5
   • Overload Potion: floor(Attack Level * 0.15) + 6
2. Calculate Effective Attack Level (EAL):

   EAL = floor((Attack Level + Potion Bonus) * Prayer Multiplier) + Attack Style Bonus + 8

   The ‘+8’ is a hidden constant in OSRS combat mechanics.

3. Calculate Player Attack Roll:

   Attack Roll = EAL * (Weapon Attack Bonus + 64)

   The ‘+64’ is another hidden constant, representing a base accuracy factor.

4. Calculate Enemy Defence Roll:

   Defence Roll = (Enemy Defence Level + 9) * (Enemy Defence Bonus + 64)

   The ‘+9’ is a hidden constant for enemy defence levels.

5. Calculate Hit Chance (%):

   This is the core of the OSRS Attack Calculator. It compares your Attack Roll against the enemy’s Defence Roll.

   • If Attack Roll > Defence Roll: Hit Chance = 1 - ((Defence Roll + 2) / (2 * (Attack Roll + 1)))
   • If Attack Roll <= Defence Roll: Hit Chance = Attack Roll / (2 * (Defence Roll + 1))

   The result is then capped between 5% and 95%.

6. Calculate Average Damage Per Hit:

   Average Damage Per Hit = Hit Chance * (Max Hit / 2)

   This assumes a uniform distribution of damage from 0 to Max Hit.

7. Calculate Damage Per Second (DPS):

   DPS = (Average Damage Per Hit / Weapon Speed in Ticks) * 0.6

   Since 1 game tick equals 0.6 seconds, this converts average damage per tick to damage per second.

8. Calculate Estimated Time to Kill (TTK):

   TTK = Enemy Hitpoints / DPS

   This gives you an estimate of how long it will take to defeat the monster.

Variables Table:

Key Variables for OSRS Attack Calculations

Variable	Meaning	Unit	Typical Range
Attack Level	Your character's Attack skill level	Level	1-99
Weapon Attack Bonus	Attack bonus from your equipped weapon and gear	Bonus	-60 to +200
Prayer Multiplier	Multiplier from active attack prayers	Multiplier	1.00 (None) to 1.23 (Turmoil)
Potion Bonus	Additive and percentage bonus from attack potions	Bonus	0 to ~15
Attack Style Bonus	Bonus from your chosen attack style (Accurate, Aggressive, Controlled)	Bonus	0 to +3
Enemy Defence Level	Target monster's Defence skill level	Level	1-300
Enemy Defence Bonus	Target monster's specific defence bonus (e.g., Slash, Stab, Crush)	Bonus	-60 to +300
Max Hit	Your maximum possible damage hit (strength-based)	Damage	1-100+
Weapon Speed	How many game ticks between your attacks	Ticks	2-8
Enemy Hitpoints	Total health of the target monster	HP	1-2000+

Practical Examples (Real-World Use Cases)

Let's look at how the OSRS Attack Calculator can be applied to common scenarios.

Example 1: Training at Sand Crabs

You're a mid-level player training Attack at Sand Crabs, aiming for efficiency.

• Your Stats: Attack Level 60, Strength Level 60 (Max Hit 20)
• Gear: Dragon Scimitar (+82 Slash), Fighter Torso, Dragon Platelegs, Dragon Defender (+25 Slash), Amulet of Fury, Berserker Ring (i)
• Prayers: No Prayer
• Potions: Super Attack Potion
• Attack Style: Aggressive (+3 Attack)
• Target: Sand Crab (Defence Level 1, Slash Defence Bonus 0, HP 60)
• Weapon Speed: 4 ticks (Dragon Scimitar)

Calculator Inputs:

• Attack Level: 60
• Weapon Attack Bonus: 82 + 25 (Defender) = 107
• Prayer Bonus: No Prayer (1.00)
• Potion Bonus: Super Attack Potion
• Attack Style Bonus: Aggressive (+3)
• Enemy Defence Level: 1
• Enemy Defence Bonus: 0
• Max Hit: 20
• Weapon Speed: 4
• Enemy Hitpoints: 60

Calculator Outputs (Approximate):

• Effective Attack Level: ~74
• Hit Chance: ~95%
• Average Damage Per Hit: ~9.5
• DPS: ~14.25
• Time to Kill (TTK): ~4.2 seconds

Interpretation: With a very high hit chance and decent DPS, Sand Crabs are highly efficient for training, as expected. The OSRS Attack Calculator confirms this by showing minimal missed attacks.

Example 2: Bossing at Vorkath

You're a high-level player attempting Vorkath, using a common melee setup.

• Your Stats: Attack Level 90, Strength Level 99 (Max Hit 50)
• Gear: Dragon Hunter Lance (+105 Stab), Elite Void Knight Top/Bottom, Void Melee Helm, Amulet of Torture, Ferocious Gloves, Dragonfire Ward, Primordial Boots, Berserker Ring (i)
• Prayers: Piety (15%)
• Potions: Super Combat Potion (acts as Super Attack)
• Attack Style: Aggressive (+3 Attack)
• Target: Vorkath (Defence Level 210, Stab Defence Bonus 100, HP 750)
• Weapon Speed: 4 ticks (Dragon Hunter Lance)

Calculator Inputs:

• Attack Level: 90
• Weapon Attack Bonus: 105 (Dragon Hunter Lance)
• Prayer Bonus: Piety (1.15)
• Potion Bonus: Super Attack Potion (from Super Combat)
• Attack Style Bonus: Aggressive (+3)
• Enemy Defence Level: 210
• Enemy Defence Bonus: 100
• Max Hit: 50
• Weapon Speed: 4
• Enemy Hitpoints: 750

Calculator Outputs (Approximate):

• Effective Attack Level: ~120
• Hit Chance: ~70%
• Average Damage Per Hit: ~17.5
• DPS: ~26.25
• Time to Kill (TTK): ~28.6 seconds

Interpretation: Even with high stats and top-tier gear, Vorkath's high defence means your hit chance is around 70%. This highlights the importance of maximizing every bonus to achieve optimal DPS against tough bosses. The OSRS Attack Calculator helps you see the impact of each gear change.

How to Use This OSRS Attack Calculator

Using the OSRS Attack Calculator is straightforward. Follow these steps to get accurate combat estimations:

1. Enter Your Attack Level: Input your current Attack skill level (1-99).
2. Input Weapon Attack Bonus: Find the relevant attack bonus (Stab, Slash, or Crush) for your equipped weapon and other gear (e.g., defender, amulet) against your target.
3. Select Prayer Bonus: Choose the attack-boosting prayer you intend to use from the dropdown.
4. Select Potion Bonus: Choose the attack-boosting potion you intend to use.
5. Select Attack Style Bonus: Pick your chosen attack style (Accurate, Aggressive, Controlled).
6. Enter Enemy Defence Level: Input the Defence level of your target monster.
7. Input Enemy Defence Bonus: Find the specific defence bonus of your target monster that corresponds to your attack style (e.g., Slash defence for a scimitar).
8. Enter Your Max Hit (Melee): This is crucial for DPS. You can use a separate OSRS Max Hit Calculator or estimate it based on your Strength level and gear.
9. Enter Weapon Speed (Ticks): Input how many game ticks your weapon takes per attack (e.g., 4 for a scimitar, 5 for a whip).
10. Enter Enemy Hitpoints: Input the total Hitpoints of the monster you are fighting.
11. Click "Calculate OSRS Attack": The results will appear below the button.

How to Read Results:

• Average Damage Per Second (DPS): This is your primary result, indicating how much damage you can expect to deal per second on average. Higher DPS means faster kills.
• Effective Attack Level: Your true attack potential after all bonuses.
• Hit Chance: The percentage probability of landing a successful hit.
• Average Damage Per Hit: The average damage you deal each time you hit.
• Estimated Time to Kill (TTK): How long it will take to defeat the enemy based on your calculated DPS.

Decision-Making Guidance:

Use the OSRS Attack Calculator to compare different gear setups, prayer choices, or potion usages. If your hit chance is very low, consider switching to a weapon with a higher attack bonus, using stronger prayers/potions, or finding a monster with lower defence. If your DPS is low but hit chance is high, focus on increasing your Max Hit (Strength level and strength bonus gear).

Key Factors That Affect OSRS Attack Calculator Results

Several variables significantly influence the outcomes of the OSRS Attack Calculator. Understanding these factors allows for better optimization of your combat setup.

1. Your Attack Level: This is the foundational factor. A higher Attack level directly increases your Effective Attack Level, leading to a higher Attack Roll and thus a better hit chance. It's the most direct way to improve accuracy.
2. Weapon Attack Bonus: The attack bonus provided by your equipped weapon and other offensive gear (e.g., defender, amulet, rings). This is a massive multiplier in the Attack Roll calculation. Choosing the correct attack style (Stab, Slash, Crush) to match the monster's weakness is crucial here.
3. Prayer Bonuses: Attack-boosting prayers like Piety, Turmoil, or even basic attack prayers provide significant percentage boosts to your Attack level, directly impacting your Effective Attack Level. These are often critical for high-level content.
4. Potion Bonuses: Attack potions, Super Attack potions, and Overload potions provide temporary boosts to your Attack level, both flat and percentage-based. These are essential for maximizing DPS during combat encounters.
5. Attack Style Bonus: Your chosen attack style (Accurate, Aggressive, Controlled) provides a small but consistent flat bonus to your Attack level. Aggressive provides +3, Controlled +1, and Accurate +0.
6. Enemy Defence Level: The target monster's Defence skill level directly contributes to its Defence Roll. Monsters with higher Defence levels are harder to hit.
7. Enemy Defence Bonus: Similar to your weapon's attack bonus, monsters have specific defence bonuses (Stab, Slash, Crush). Attacking with the style they are weakest to significantly reduces their Defence Roll, increasing your hit chance.
8. Your Max Hit: While not directly an "attack" stat, your Max Hit (determined by Strength level and strength bonus) is critical for DPS. A high hit chance with a low Max Hit will result in low DPS. The OSRS Attack Calculator uses your provided Max Hit to calculate average damage.
9. Weapon Speed: How quickly your weapon attacks (in game ticks) directly affects your DPS. A faster weapon, even with slightly lower Max Hit, can sometimes outperform a slower, harder-hitting weapon due to more frequent damage application.

Frequently Asked Questions (FAQ)

Q1: How accurate is this OSRS Attack Calculator?
A1: This calculator uses the widely accepted OSRS combat formulas for hit chance and DPS. While it provides highly accurate estimates based on averages, actual combat involves randomness, so results are probabilities, not guarantees. It does not account for special attacks or specific monster mechanics beyond their base stats.

Q2: Does this calculator include Strength level?
A2: No, this OSRS Attack Calculator focuses on accuracy (hit chance) which is primarily determined by your Attack level. Your Strength level and strength bonus gear determine your Max Hit. You need to input your Max Hit separately for the DPS calculation. For a tool that calculates Max Hit, refer to our OSRS Max Hit Calculator.

Q3: What about Magic or Ranged attacks?
A3: This specific calculator is designed for Melee attack calculations. Magic and Ranged combat have different underlying formulas for accuracy and damage. We plan to offer dedicated calculators for those combat styles in the future.

Q4: Why is my DPS so low even with high Attack?
A4: Low DPS can stem from several factors. It could be a low Max Hit (meaning you need more Strength or strength bonus gear), a very high-defence monster (leading to low hit chance), or a slow weapon. Use the intermediate results (Hit Chance, Average Damage Per Hit) to pinpoint the bottleneck.

Q5: What are common prayer and potion bonuses?
A5: Common attack prayers include Clarity of Thought (5%), Improved Reflexes (10%), Piety (15%), and Turmoil (23%). Common potions include Attack Potion (+3), Super Attack Potion (+5 + 15% of Attack Level), and Overload Potion (+6 + 15% of Attack Level).

Q6: Can I use this to compare different gear setups?
A6: Absolutely! This is one of the primary uses of the OSRS Attack Calculator. By changing your Weapon Attack Bonus and Max Hit inputs, you can quickly see how different gear combinations impact your DPS and hit chance against a specific target.

Q7: What is the "hidden constant" in OSRS combat?
A7: OSRS combat formulas include several "hidden constants" that are not explicitly stated in-game but are derived through extensive community testing. For example, the +8 in Effective Attack Level and +64 in Attack/Defence Rolls are such constants that ensure the formulas accurately reflect game mechanics.

Q8: How does the "Attack Style Bonus" work?
A8: Your chosen attack style (e.g., Accurate, Aggressive, Controlled) provides a small flat bonus to your Attack level before other calculations. Aggressive gives +3, Controlled gives +1, and Accurate gives +0. This can be a minor but impactful boost, especially at lower levels.

Related Tools and Internal Resources

To further enhance your Old School RuneScape combat experience, explore these related tools and guides:

• OSRS Max Hit Calculator: Determine your maximum possible damage hit based on your Strength level and gear.
• OSRS DPS Calculator: A more comprehensive DPS calculator that might include more advanced mechanics.
• OSRS Gear Optimizer: Find the best gear setups for specific combat scenarios.
• OSRS XP Calculator: Plan your training and estimate time to reach desired skill levels.
• OSRS Prayer Guide: Learn about all available prayers and their effects.
• OSRS Potion Guide: Understand the various combat potions and their benefits.