Burn Surface Area (Rule of Nines) — free guideline decision tool
Estimate adult burn surface area (%TBSA) with the Wallace rule of nines.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Head & neck (max 9%) | Front/back (4.5) |
|---|---|
| Right arm (max 9%) | Front/back (4.5) |
| Left arm (max 9%) | Front/back (4.5) |
| Anterior trunk (max 18%) | Chest or abdomen (9) |
| Posterior trunk (max 18%) | Half (9) |
| Right leg (max 18%) | Front/back (9) |
| Left leg (max 18%) | Front/back (9) |
| Perineum (max 1%) | None (0) |
→Total burn surface area49.5 % TBSA
- Area：49.5% (Large area (aggressive fluid resuscitation)). Count second-degree and deeper only
- Resuscitation：≥ 15–20% TBSA needs formal fluid resuscitation. Parkland: 24 h lactated Ringer's = 4 mL × weight (kg) × %TBSA = 198 mL/kg body weight, half in the first 8 h (from time of injury), titrated to urine output 0.5–1 mL/kg/h
- Small/scattered：Palm method: the patient's palm (incl. fingers) ≈ 1% TBSA
| Head & neck (max 9%) | None (0) |
|---|---|
| Right arm (max 9%) | None (0) |
| Left arm (max 9%) | None (0) |
| Anterior trunk (max 18%) | None (0) |
| Posterior trunk (max 18%) | None (0) |
| Right leg (max 18%) | None (0) |
| Left leg (max 18%) | None (0) |
| Perineum (max 1%) | None (0) |
→Total burn surface area0 % TBSA
- Area：0% (Smaller area). Count second-degree and deeper only
- Resuscitation：≥ 15–20% TBSA needs formal fluid resuscitation. Parkland: 24 h lactated Ringer's = 4 mL × weight (kg) × %TBSA = 0 mL/kg body weight, half in the first 8 h (from time of injury), titrated to urine output 0.5–1 mL/kg/h
- Small/scattered：Palm method: the patient's palm (incl. fingers) ≈ 1% TBSA
Common questions
What is Burn Surface Area (Rule of Nines)?
Estimate adult burn surface area (%TBSA) with the Wallace rule of nines.
How is Burn Surface Area (Rule of Nines) calculated? What is the core formula?
Head/neck 9, each arm 9, anterior/posterior trunk 18 each, each leg 18, perineum 1 (100% total). Count second-degree and deeper only. Map second-degree and deeper burns to adult Wallace percentages (head/neck 9, each arm 9, anterior trunk 18, posterior trunk 18, each leg 18, perineum 1); use palm-including-fingers ≈1% for patchy areas.
When is Burn Surface Area (Rule of Nines) used?
Guide burn fluid resuscitation and burn-center referral.
How should Burn Surface Area (Rule of Nines) results be interpreted?
Adults with roughly ≥15–20% TBSA usually need formal fluid resuscitation (often Parkland) and burn-centre referral thresholds per local criteria.
What are the key clinical points for Burn Surface Area (Rule of Nines)?
≥ 15–20% TBSA needs formal fluid resuscitation (Parkland). Palm (incl. fingers) ≈ 1% TBSA for small burns. Use the Lund-Browder chart in children.
What are the limits and cautions when using Burn Surface Area (Rule of Nines)?
Do not count first-degree (erythema-only) burns toward %TBSA. Children need Lund-Browder charts — adult nines overestimate paediatric head contribution incorrectly if misapplied. Reassess after debridement; initial ED estimates often change. For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does Burn Surface Area (Rule of Nines) upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
How is Burn Surface Area (Rule of Nines) calculated in practice? Can you show a worked example?
Inputs: Head & neck (max 9%) Front/back (4.5), Right arm (max 9%) Front/back (4.5), Left arm (max 9%) Front/back (4.5), Anterior trunk (max 18%) Chest or abdomen (9), Posterior trunk (max 18%) Half (9), Right leg (max 18%) Front/back (9), Left leg (max 18%) Front/back (9), Perineum (max 1%) None (0) → Result: Total burn surface area 49.5 % TBSA（Area: 49.5% (Large area (aggressive fluid resuscitation)). Count second-degree and deeper only, Resuscitation: ≥ 15–20% TBSA needs formal fluid resuscitation. Parkland: 24 h lactated Ringer's = 4 mL × weight (kg) × %TBSA = 198 mL/kg body weight, half in the first 8 h (from time of injury), titrated to urine output 0.5–1 mL/kg/h, Small/scattered: Palm method: the patient's palm (incl. fingers) ≈ 1% TBSA） Inputs: Head & neck (max 9%) None (0), Right arm (max 9%) None (0), Left arm (max 9%) None (0), Anterior trunk (max 18%) None (0), Posterior trunk (max 18%) None (0), Right leg (max 18%) None (0), Left leg (max 18%) None (0), Perineum (max 1%) None (0) → Result: Total burn surface area 0 % TBSA（Area: 0% (Smaller area). Count second-degree and deeper only, Resuscitation: ≥ 15–20% TBSA needs formal fluid resuscitation. Parkland: 24 h lactated Ringer's = 4 mL × weight (kg) × %TBSA = 0 mL/kg body weight, half in the first 8 h (from time of injury), titrated to urine output 0.5–1 mL/kg/h, Small/scattered: Palm method: the patient's palm (incl. fingers) ≈ 1% TBSA）
Run Burn Surface Area (Rule of Nines) now
Estimate adult burn surface area (%TBSA) with the Wallace rule of nines.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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