DPS calculator

This calculator computes your melee max hit using the standard Old School RuneScape formula, with custom additions (Divine Overload, Sanguine Scythe of Vitur, Royal/Divine zone). It is the first step toward a full DPS calculator; accuracy and attack speed are not modelled yet.

Formula

Boosted Strength    = floor(Strength + Potion Boost)
Effective Strength  = floor((Boosted Strength + Style Bonus + 8) × Prayer Multiplier)
Max Hit             = floor(Effective Strength × (Strength Bonus + 64) / 640)
Sanguine Max Hit    = floor(Max Hit × 1.05)   (Sanguine Scythe of Vitur only, +5% vs NPCs)
Salve Max Hit       = floor(Sanguine Max Hit × 1.20)   (Salve Amulet (ei), vs undead only)
Zone Max Hit        = floor(Salve Max Hit × 1.10)   (only in Royal/Divine zone)

Boosts

Potion	Strength boost
Super Combat Potion	5 + floor(Level × 0.15)  (+19 at 99)
Smouldering Heart/CoX Overload	6 + floor(Level × 0.16)  (+21 at 99)
Divine Overload	5 + floor(Level × 0.22)  (+26 at 99) — estimate

Prayers

Prayer	Multiplier
Burst of Strength	×1.05
Superhuman Strength	×1.10
Ultimate Strength	×1.15
Chivalry	×1.18
Piety	×1.23

Attack styles

Style	Bonus
Aggressive	+3
Controlled	+1
Accurate / Defensive	+0

Other modifiers

Effect	Multiplier	Notes
Salve Amulet (ei)	×1.20	vs undead only; applied before the Royal/Divine zone
Royal/Divine zone	×1.10	applied last, before the scythe split

Scythe of Vitur

The Scythe of Vitur splits its max hit into multiple hits depending on the NPC size; every hit rounds down individually. Example with a max hit of 51: 51-25-12.

Weapon	NPC size	Hits
Scythe of Vitur	Small (1×1)	[max]
Scythe of Vitur	Medium (2×2)	[max, floor(max / 2)]
Scythe of Vitur	Large (3×3+)	[max, floor(max / 2), floor(max / 4)]
Sanguine Scythe of Vitur	Any (except 2×2)	[max, floor(max / 2), floor(max / 2), floor(max / 4)]
Sanguine Scythe of Vitur	2×2 (bugged)	[max, floor(max / 2), floor(max / 2)], only 3 hits instead of 4
Holy Scythe of Vitur	Any	[max, floor(max / 2), floor(max / 4)]

Note: The Sanguine Scythe is intended to hit 4× on all NPC sizes, but 2×2 NPCs are currently bugged and only receive 3 hits. It also deals +5% damage vs NPCs. In-game verified: 2×2 max 15 -> 15-7-7, max 10 -> 10-5-5; 1×1 max 8 -> 8-4-4-2.

Note: The Divine Overload boost is an assumption (5 + floor(Level × 0.22) matches the +26 boost at 99 Strength from the update notes). I need Divine to verify it. People probably only care about the +26 anyways.