Rule of Nines (Burns)
Rapid estimation of total body surface area (TBSA) burned
Calculator
Why use it
Rapid bedside TBSA estimation without specialized tools. Standard method taught in ATLS and burn management protocols. Required for Parkland formula fluid resuscitation calculation and for determining burn center transfer criteria.
About
The Rule of Nines divides the adult body surface area into regions each representing approximately 9% (or multiples of 9%) of total body surface area (TBSA). It provides a rapid, anatomically based estimate of burn extent used to guide fluid resuscitation (Parkland formula) and initial management of burn patients. Only partial-thickness and full-thickness burns are included — superficial (first-degree) burns equivalent to sunburn are excluded.
When to use
- Initial assessment of burn injury in emergency department or pre-hospital setting
- Fluid resuscitation calculation (feeds directly into Parkland formula)
- Burn center transfer criteria determination (major burns ≥ 10–20% TBSA)
- Burn severity classification
Formula
Pearls & pitfalls
- Only include 2nd and 3rd degree (partial and full thickness) burns — NOT superficial (1st degree/sunburn).
- In children: the head is 18% (not 9%), and each leg is 14% (not 18%). Use Lund-Browder chart for pediatric patients.
- Palmar surface method: patient's palm (including fingers) ≈ 1% TBSA — useful for small or patchy burns.
- TBSA > 20% in adults or > 10% in children/elderly requires Parkland formula and inpatient resuscitation.
- Inhalation injury adds significant morbidity independent of TBSA.
- The Lund-Browder chart is more accurate than Rule of Nines, especially in children.
Next steps
Use TBSA result in Parkland formula: Total fluids (mL) = 4 × Weight (kg) × %TBSA. Burn center referral: TBSA ≥ 10% in pediatric/elderly, ≥ 20% in adults; any full-thickness burns; burns of special areas (face, hands, feet, genitalia, joints); inhalation injury; circumferential burns.
Evidence
Originally developed by Pulaski & Tennison and popularized by Wallace (1951). Standard method in ATLS, ABLS (Advanced Burn Life Support), and international burn management guidelines. Validated as a practical tool in emergency settings despite less accuracy than Lund-Browder.