Calculator Form
Example Data Table
| Setup | Attack Level | Attack Bonus | Target Defence | Defence Bonus | Max Hit | Speed |
|---|---|---|---|---|---|---|
| Melee Boss Setup | 99 | 120 | 100 | 80 | 35 | 4 |
| Ranged Training Setup | 90 | 105 | 75 | 55 | 28 | 4 |
| Magic Target Setup | 94 | 95 | 85 | 70 | 32 | 5 |
Formula Used
Effective Attack = floor((Attack Level × Potion Multiplier) × Prayer Multiplier) + Style Bonus + 8.
Attack Roll = floor(Effective Attack × (Attack Bonus + 64) × Set Multiplier × Special Multiplier).
Effective Defence = floor(Target Defence Level × Defence Modifier) + 8.
Defence Roll = floor(Effective Defence × (Target Defence Bonus + 64)).
If attack roll is greater than defence roll, hit chance equals 1 - ((defence roll + 2) / (2 × (attack roll + 1))).
If attack roll is equal to or lower than defence roll, hit chance equals attack roll / (2 × (defence roll + 1)).
Expected DPS = final hit chance × average hit ÷ seconds per attack.
How To Use This Calculator
Enter your combat style first. Add the level that controls your accuracy roll.
Add your equipment attack bonus for the chosen style. Use slash, stab, crush, ranged, or magic as needed.
Enter prayer, potion, set, and special attack multipliers. Use 1.00 when no bonus applies.
Add the target defence level and matching defence bonus. Then enter maximum hit and weapon speed.
Press calculate. The result appears below the header and above the form.
Use CSV for spreadsheet work. Use PDF for reports or quick sharing.
Advanced RuneScape Hit Chance Guide
Why Hit Chance Matters
Hit chance shows how often an attack should land. It helps compare weapons, gear, prayers, potions, and targets. A high max hit can still perform poorly. That happens when accuracy is too low. A balanced setup usually works better. This calculator makes that balance easier to see.
Understanding Attack Rolls
The attack roll represents your chance to beat defence. It uses your accuracy level and equipment bonus. Prayer and potion boosts can raise the effective value. Style bonuses can also matter. Special attacks may include accuracy multipliers. Enter those multipliers as decimal values. For example, use 1.25 for a twenty five percent boost.
Understanding Defence Rolls
The defence roll represents the target resistance. Strong monsters often have high defence levels. They may also have strong style defence bonuses. Always match the defence bonus to your attack type. A slash attack should use slash defence. A magic attack should use magic defence. Wrong inputs can create misleading estimates.
Reading The Result
The final hit chance is the main output. Miss chance is the remaining percentage. Expected hits estimate successful attacks over your chosen count. Expected damage per swing combines accuracy and average hit. Estimated DPS adds attack speed. Faster weapons can perform well with lower max hits. Slower weapons need stronger damage or better accuracy.
Planning Better Combat
Use the form to test several setups. Change one value at a time. Compare attack bonus, prayers, and target defence. This makes upgrades easier to judge. It also helps decide when accuracy gear beats strength gear. For difficult fights, accuracy can save supplies. For weak targets, damage gear may be stronger. The best choice depends on the target.
Practical Notes
This tool gives a planning estimate. Real fights include movement, mechanics, delays, and mistakes. Some weapons have special rules. Some effects change damage after accuracy is rolled. Use the custom multiplier fields for advanced adjustments. Save results with CSV or PDF. Review them before changing gear. Better data leads to better combat decisions.
FAQs
What does this calculator estimate?
It estimates hit chance, miss chance, attack roll, defence roll, expected hits, expected misses, expected damage per swing, and estimated DPS.
Can I use it for melee, ranged, and magic?
Yes. Choose the style and enter matching attack and defence bonuses. The formula works best when the entered bonuses match the selected combat type.
What should I enter for prayer multiplier?
Enter the decimal form of your accuracy boost. Use 1.00 for no boost, 1.05 for five percent, and 1.15 for fifteen percent.
What is flat hit chance bonus?
It is an extra percentage added after the base roll formula. Use it only for effects that directly add hit chance.
Why does attack speed use ticks?
RuneScape combat timing is often measured in game ticks. This calculator treats one tick as 0.6 seconds for estimated DPS.
Why is my hit chance low?
Your target may have strong defence. Your attack bonus may also be weak for that style. Try testing better gear, prayers, potions, or another combat style.
Does this guarantee exact fight damage?
No. It estimates average results. Real fights include movement, delays, special mechanics, overkill, player mistakes, and random variation.
Can I export the results?
Yes. Use the CSV button for spreadsheet data. Use the PDF button after calculating to save a readable result summary.