Gaming · D&D 5e
Death saving throw odds calculator.
Enter your save bonus and how often the enemy keeps hitting the downed character. The tool follows every possible sequence of rolls and reports the chance to live.
The downed character
Result
Enter your numbers and press Calculate.
What this calculator does
A downed character rolls a d20 at the start of every turn. The SRD says 10 or higher is a success, anything lower a failure, a natural 1 counts as two failures, and a natural 20 lets you regain 1 hit point. Three successes make you stable, three failures kill you. The question players ask is simply how likely they are to come out alive, and the answer is not 50 percent.
With no bonus and nobody hitting you, the exact answer is 59.5%: 41.4% by collecting three successes, plus 18.1% by rolling a natural 20 first. The remaining 40.5% is death. This calculator walks every branch of the roll sequence, so you can change the bonus, the roll mode and how often the party is still being attacked, and see the figure move.
Worked example
Take a character with no bonus and no one attacking. Each roll is a natural 20 5% of the time, a success on 10 to 19 50%, a failure on 2 to 9 40% and a natural 1 5%. Following every sequence gives 59.5% survival. A +2 bonus lifts that to 73.7%, advantage to 94.7%. Now keep the plain roll but let a monster hit the downed character half the time, with one hit in ten a critical: survival falls to 33.1%.
How it is calculated
Each roll is one of four outcomes. The d20 face is read first: 20 revives, 1 is two failures, and 2 to 19 is a success when face plus bonus reaches 10 and a failure otherwise. A bonus never turns a natural 1 into anything but two failures, and a natural 20 always revives, because the SRD gives those faces their own effect. With advantage or disadvantage the face probabilities become (2k-1)/400 and (41-2k)/400 for face k, the standard best-of-two and worst-of-two distribution. After each roll that does not end the sequence, the tool applies one damage event with the chance you entered: a hit is one failure, a critical hit two. Reaching three of either kind ends the sequence. Rounds are repeated until no sequence is left, which takes at most five rolls.
Death saving throws are in the Combat chapter of SRD 5.1 (page 98), under "Death Saving Throws". The survival percentages are computed by this tool from those rules and are not published figures. Last checked 2026-10-26.
What this does not cover
- Instant death from damage equal to your hit point maximum is not modelled; enter a lower hit chance if the enemy can do that.
- Healing or a first-aid check that ends the sequence is not modelled, so the figures show the unaided character.
- Spells and features that change what a roll counts as are covered only if they are a flat bonus or advantage.
- The model assumes one damage event between turns. If several attackers act, raise the hit chance.
Common mix-ups
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Often assumedDeath saves are basically a coin flip, so a downed character lives about half the time.
What the source saysThe SRD makes a roll of 10 or higher a success, counts a natural 1 as two failures and lets a natural 20 bring you back with 1 hit point, so the real outcome mix is not even. [1]
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Often assumedRolling a natural 20 on a death save gets you back into the fight in good shape.
What the source saysThe SRD says you regain 1 hit point on a natural 20. You are conscious but one hit from being down again. [1]
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Often assumedDamage only matters to a downed character if it is large enough to kill outright.
What the source saysThe SRD says any damage taken at 0 hit points causes a death save failure, two if it came from a critical hit. Only damage at or above your hit point maximum is instant death. [1]
Checked against these sources on .
Frequently asked questions
What is the chance of surviving death saving throws in 5e?
With a flat d20, no bonus and no further damage, it is 59.5%. That is 41.4% to reach three successes and 18.1% to roll a natural 20 first. The other 40.5% ends in death.
Does a natural 20 on a death save heal you?
It returns you to consciousness with 1 hit point, according to the SRD. It is not a full recovery, and you are still one hit from going down again.
How does taking damage while at 0 hit points work?
The SRD treats any damage you take at 0 hit points as one death save failure, and two failures if the damage comes from a critical hit. Damage equal to or above your hit point maximum kills you outright.
How much does advantage help on death saves?
Advantage on every roll raises survival from 59.5% to 94.7% in the no-damage case, because it makes both natural 20s and successes more common and natural 1s rarer.
Do successes and failures need to be consecutive?
No. The SRD says they do not need to be consecutive, you keep both tallies until you reach three of one kind. The counts reset when you regain any hit points or become stable.
Sources
Checked
Death saving throws are in the Combat chapter of SRD 5.1 (page 98), under "Death Saving Throws". The survival percentages are computed by this tool from those rules and are not published figures. Runs entirely in your browser. Nothing you type is sent or stored.
Disclaimer
TNAADO is not affiliated with Wizards of the Coast. This tool is compatible with fifth edition and uses game names only to describe what it is for. Odds and totals are arithmetic from the cited rules, and your table's house rules may differ. This work includes material taken from the System Reference Document 5.1 ("SRD 5.1") by Wizards of the Coast LLC and available at https://dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at https://creativecommons.org/licenses/by/4.0/legalcode.