Diablo 4 Tool · Free · Offline
Diablo 4 Build Calculator
Paste your sheet stats — get real capped values, wasted-stat warnings, and your true attacks per second. The math everyone half-remembers, done exactly.
The caps this calculator applies
Diablo 4 hides several ceilings behind one sheet number. The most common trap is attack speed: the stack shows everything added together, but the engine applies two separate 100% caps — plain "Attack Speed" sources belong to Cap 1 and "Cast Speed" sources (most channelled and spell-cast abilities) belong to Cap 2. Each multiplies your weapon's base attacks per second, which is why the same 80% speed bonus feels completely different on a slow two-hander than on dual daggers.
Critical Strike Chance has a 100% ceiling — past it every extra point is dead weight, and gear slots spent on it are wasted investment. Resistances top out at 85%, the value every endgame build targets for Torment content; short of that, each percentage point matters, beyond it you are paying for nothing. Checking these three before respec'ing typically frees several affix rolls for damage or survivability.
The calculator is pure client-side math — it makes no network calls at all, so it works in game-window alt-tab sessions and never transmits anything. For deeper mechanics research, Maxroll keeps the authoritative write-ups on attack speed mechanics and paragon boards, and our Paragon Planner covers the point-budget and glyph math.
Frequently asked questions
Does this calculator need an account or API keys?
No. Everything runs locally in your browser with pure JavaScript — nothing is sent anywhere, so it works offline and never touches your data.
What are the Diablo 4 stat caps it uses?
Attack Speed% is capped at 200% total but split into two 100% caps: "Attack Speed" sources (Cap 1) and "Cast Speed" sources (Cap 2) multiply separately. Resistance is capped at 85%, and critical strike chance above 100% does nothing. Mechanics follow Maxroll's documented D4 attack-speed and cap articles.
Why does my attacks-per-second number matter?
Your final ApS is your weapon's base attacks-per-second multiplied by both speed caps — so a faster-base weapon multiplies every point of attack speed you invest. Two weapons with identical speed bonuses can differ hugely after the caps are applied.
What counts "wasted" attack speed?
Anything over 100% in a single cap contributes nothing: 200% attack speed from Cap-1 sources only counts once. The calculator shows exactly how much of your sheet value is dead weight so you can swap affixes for something else.
Example: capped build check
Input: 1.10 base ApS, 120% Attack Speed (Cap 1), 80% Cast Speed (Cap 2), 95% crit, 90% resistance. Result: real ApS = 1.87, wasted AS = 20%, wasted res = 5%. Verdict: swap Affixes for damage or survivability.