A splint is the largest single factor: pzwiki states it makes a fracture heal about 10x faster than leaving it unsplinted, and it is also the only way to stop the ongoing HP loss a fracture causes. First Aid skill multiplies healing speed further — the game’s own per-level table runs from 50% at level 0 up to 550% at level 10, which works out to roughly 1x to 11x relative to level 0. A comfrey poultice on top of that cuts whatever time is left by half. There is no absolute day count for an unsplinted fracture published on the pages we could open — pzwiki’s Health page lists a wide range (up to roughly 60 in-game days at the Normal healer trait, with no stated minimum) rather than a fixed number, so this page gives you the relative math instead of inventing a baseline.
Correction — 13 September 2026: the 5 September 2026 correction on this page withdrew an invented 18-day baseline and its multipliers because they were not extracted from the game. That withdrawal is still correct — there is no calibrated absolute baseline here — but it went too far and removed the answer entirely. This revision restores what pzwiki’s own pages state about relative healing speed (splint, First Aid level, comfrey) without reintroducing an invented day count.
What each factor does, in pzwiki’s own words
- Splint. “Splints make fractures heal 10x faster… Using a splint is the only way to stop losing HP due to fractures.” A separate line on the same page adds: “Each first aid level of the applying player will increase the healing rate by an additional factor of 5” — see the note on the contradiction below.
- First Aid level. The First Aid page’s “Fracture healing speed multiplier” table: 50% at level
0, then +50 percentage points per level up to 550% at level 10. Relative to level 0, that is a
straight
1 + levelmultiplier (level 4 is 5x level 0, for example). - Comfrey poultice. “Apply comfrey, reducing the recovery time of a fracture by 50%” — this halves whatever time remains, i.e. it doubles speed from that point.
- What cannot be splinted. Head and torso fractures cannot be splinted at all, per both the First Aid and Health pages; a torso fracture also caps the character’s effective maximum health around 60% while it is active (pzwiki, Health).
A contradiction we are not smoothing over: the Splint page’s “additional factor of 5 per first
aid level” and the First Aid page’s per-level table (which implies roughly 1 + level, not a
repeated ×5) describe the same interaction differently, and neither page states how the two would
stack together. This page computes from the First Aid table, because it gives an explicit value at
every level; the “factor of 5” line is quoted above but not built into the calculator.
Relative speed calculator
Everything below is a ratio to one reference point: an unsplinted fracture at First Aid level 0, no comfrey. It does not output a day count, because pzwiki does not publish one to calibrate against.
Relative fracture healing speed
- Speed, relative to an unsplinted fracture at First Aid 0
- 10x
- Time to heal, as a fraction of that same baseline
- 10%
Head and torso fractures cannot be splinted (pzwiki, First Aid / Health).
Ratios only, taken from pzwiki's Splint and First Aid pages (checked 2026-09-13). No absolute day count is asserted; the game does not publish one on the pages we could open.
For example, a splint applied by a First Aid level 4 character with a comfrey poultice comes out to
10 × 5 × 2 = 100x the reference speed, i.e. about 1% of the unsplinted-level-0 healing time —
using the First Aid table’s ratios, not the Splint page’s “factor of 5” wording.
Reference table and a secondary supply planner
| Level | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Multiplier | 50% | 100% | 150% | 200% | 250% | 300% | 350% | 400% | 450% | 500% | 550% |
Splint page: “Splints make fractures heal 10x faster… Each first aid level of the applying player will increase the healing rate by an additional factor of 5.” That is a different claim from the First Aid table above and the two are not reconciled on either page — this site computes from the First Aid table, not the “factor of 5” line, because the table gives an explicit per-level value and the other line does not say how it stacks.
First Aid page: comfrey “reduc[es] the recovery time of a fracture by 50%.” Head and torso fractures cannot be splinted.
Supply planner for a chosen interval (secondary — not a healing forecast)
48 portions for the chosen 16-day interval. This is not a healing forecast.
Your chosen duration × your observed daily use, including a reserve. This does not predict fracture healing, nutrition, spoilage or game mechanics.
What this page is not
This is a healing-speed reference, not a survival checklist. If the fracture happened away from a safe base and you are managing bleeding, threats or distance right now, the broken-leg field-survival tracker is the ordering tool for that; this page only answers “what makes it heal faster.”
Sources
- PZwiki, Splint — read in full 22 September 2026. “Splints make fractures heal 10x faster”; splinting is the only way to stop fracture HP loss; the separate “additional factor of 5” per First Aid level line. Page stamped 42.10.0; current stable is 42.20.4.
- PZwiki, First Aid — read in full 22 September 2026. The Fracture healing speed multiplier table (50% at level 0 to 550% at level 10); head and torso fractures cannot be splinted; comfrey reduces recovery time by 50%; being well fed adds a separate 30%. Page stamped 42.18.0; current stable is 42.20.4.
- PZwiki, Health — read in full 22 September 2026. Fracture severity table gives ”? – 60” in-game days at the Normal healer trait (”? – 140” Slow Healer, ”? – 40” Fast Healer); a torso fracture caps effective max health around 60%. Page stamped 42.15.3; current stable is 42.20.4.
- PZwiki, Comfrey — read in full 22 September 2026. Quotes the in-game tooltip “Aids recovery from broken bones when applied as a poultice.” The 50% fracture figure itself is on the First Aid page, not here. Page stamped 42.3.1; current stable is 42.20.4.
- Developer API: BodyPart — checked 22 September 2026. Method signatures for fracture and splint state; no calibrated day-count formula in the method list.
- Steam news, Project Zomboid news hub — checked 22 September 2026. Confirms “42.20.4 STABLE & 42.19.2 UNSTABLE & 41.78.21 LEGACY Hotfixes Released,” dated 26 August 2026, as the most recent stable release.
