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D&D Spell Slot Calculator

Estimate single-class spell slots for full casters, half casters, third casters, and warlocks with short-rest recovery.

Last updated: 2026-03-16

D&D spell slot calculator

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Estimate spell slots for a single-class caster progression, including warlock pact magic and short-rest recovery.

All required fields must be filled in.

Slot Progression

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Choose a caster progression and level to see the available spell-slot ladder.

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Example calculations

Tap an example to prefill the calculator with sample values.

Level 5 wizard

Full caster hitting 3rd-level spells

A classic breakpoint where the spell list expands sharply and resource planning changes.

Result: Access to 3rd-level spells with nine long-rest slots total

Level 9 ranger

Half caster moving into 3rd-level utility

Useful for checking when the next tier of prepared spells and slots actually arrives.

Result: A lighter slot ladder with just enough depth for staple upcasts

Level 11 warlock

Pact slots plus the first Mystic Arcanum

Warlock resource math is very different, so short rests meaningfully change the daily cast count.

Result: Short-rest pact slots plus one 6th-level Arcanum cast

How the slot planner works

The calculator maps a level to a single-class caster progression and then summarizes the slot ladder in a more glanceable format than a class table. It is strongest when you just need to know what opens up at the next level.

Warlocks are handled differently because short rests change the total daily cast count. That is why the tool asks for expected short rests instead of only listing a static pact-slot row.

Spell slot FAQs

What is covered, what is simplified, and why warlocks are treated separately.

Does this handle multiclass spellcasting?

No. It is a quick single-class planner. Multiclass slot rules are more involved and need a dedicated rules engine.

How are warlocks handled?

Warlocks use Pact Magic instead of the normal long-rest slot ladder, so the calculator shows pact slots, short-rest recovery, and Mystic Arcanum separately.

Is this meant to replace the class table in the book?

No. It is a planning shortcut. Use it to check breakpoints and daily casting capacity, then confirm final rules at the table if a build has special exceptions.

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