Interpretation
| Result | Meaning |
|---|---|
| < 10% | Minor/moderate |
| 10–19% | Burn-centre referral if partial thickness >10% |
| ≥ 20% | Formal fluid resuscitation; burn centre |
Formula
TBSA % = sum of fully burned regions: head/neck 9 · each upper limb 9 · anterior trunk 18 · posterior trunk 18 · each lower limb 18 · perineum 1, plus any extra % (patient palm with fingers ≈ 1%).
Clinical pearls
- Do not count superficial (first-degree, erythema only) burns; include only partial- and full-thickness.
- Adults only: children have proportionally larger heads and smaller legs, so use a Lund-Browder chart.
- For a region only partly burned, leave it unchecked and add its burned share under "additional %" (e.g. front of one arm ≈ 4.5%).
Examples
rule of nines burns to chest, abdomen and right armtbsa burn whole back and both legsrule of 9s left leg plus 3 percent scattered
FAQ
What is the rule of nines?
An adult burn-size estimate dividing the body into 9% regions: head 9, each arm 9, front trunk 18, back trunk 18, each leg 18, perineum 1.
Does the rule of nines work for children?
No. A child's head is a larger share of body surface; use the Lund-Browder chart for children.