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Rule of nines burn calculator
Choose the patient, then tap every region with partial- or full-thickness burns. Superficial burns — reddened skin only — are not counted.
Patient
Regions burned
0%
Estimated total body surface area burned
The proportions
| Region | Adult | Child | Infant |
|---|---|---|---|
| Head and neck | 9% | 12% | 18% |
| Anterior trunk | 18% | 18% | 18% |
| Posterior trunk | 18% | 18% | 18% |
| Right arm | 9% | 9% | 9% |
| Left arm | 9% | 9% | 9% |
| Right leg | 18% | 16.5% | 13.5% |
| Left leg | 18% | 16.5% | 13.5% |
| Genitalia | 1% | 1% | 1% |
Children have proportionally larger heads and smaller legs, which is why their columns differ. For scattered burns, the patient's own palm is roughly 1% of their body surface.
Practice it where it is scored
Every CinnaEMS question comes with a written rationale, scored by the 2025 National Registry domains.