dnd fall damage calculator - Aaron Graves, PhDude Replica

Fall Damage Calculator (D&D 5e Style)

Uses the core rule: 1d6 bludgeoning per 10 feet fallen, up to 20d6 maximum.

Fall distance (feet)

Current HP (optional, for survival check)

Max HP (optional, for instant death rule)

Flat damage reduction (optional, e.g., Monk Slow Fall)

Damage modifiers

Resistance to bludgeoning Vulnerability to bludgeoning Immunity to bludgeoning Feather Fall active

Use a simulated dice roll for HP outcome (instead of average)

How fall damage works in D&D

Falling is one of those classic tabletop moments: missed ledges, collapsing bridges, thunderwave off a cliff, or a risky leap that fails. In standard 5e-style rules, fall damage is simple:

You take 1d6 bludgeoning damage per 10 feet fallen.
The damage is capped at 20d6 (effectively 200 feet or more).
Damage is rolled when you hit the ground (unless a feature changes it).

What this calculator includes

This tool is designed for quick table use and encounter prep. It calculates:

Raw fall damage dice, range, and average.
Damage adjustments from resistance, vulnerability, immunity, or Feather Fall.
Optional flat reduction (great for class features like Slow Fall).
A survival/instant-death check if you enter current HP and max HP.

Important rule interactions

Resistance and vulnerability

If a creature has resistance to bludgeoning damage, damage is halved (rounded down). If it has vulnerability, damage is doubled. If both apply, they cancel each other out.

Immunity and Feather Fall

Immunity to bludgeoning sets fall damage to zero. Feather Fall also prevents fall damage on landing, so this calculator treats it as zero damage.

Flat damage reduction

Some features reduce incoming damage by a fixed amount. Enter that in the flat reduction field and the calculator subtracts it after multipliers, minimum 0.

Examples

30-foot fall

A 30-foot drop is 3d6 damage. That means:

Minimum: 3
Maximum: 18
Average: 10.5

120-foot fall with resistance

A 120-foot drop is 12d6. Average raw damage is 42. With resistance, average applied damage becomes 21 (rounded down where needed).

Huge drop beyond 200 feet

By default 5e rules, damage caps at 20d6, so whether you fall 200 feet or 2,000 feet, the rolled damage is still capped unless your DM uses house rules.

Instant death reminder

When damage drops a creature to 0 HP, check excess damage. If the excess is equal to or greater than the creature’s max HP, that creature dies instantly. Otherwise, it falls unconscious and begins death saving throws.

DM and player tips

Track vertical distance clearly: map height, cliffs, towers, and flight altitude matter.
Ask about reactions: monks, spells, and class features can dramatically reduce fall risk.
Decide house rules early: if your table uses custom terminal velocity or terrain impact rules, keep them consistent.
Use for encounter design: vertical maps are fun, but lethal drops can swing difficulty quickly.

FAQ

Does landing in water remove damage?

Not by default in basic 5e text. Some DMs reduce damage based on depth or circumstances as a house rule.

Does being prone change fall damage?

Not directly. Fall damage is based on distance and modifiers, not condition at impact.

Can I use this for other editions?

This calculator is tuned to 5e-style fall damage. Other systems and editions may use different formulas.