Burns BSA — Rule of Nines — Free Online Calculator
Affected Body Regions (Adult Rule of Nines)
Note: This uses the adult Rule of Nines. Pediatric patients have proportionally larger head and smaller leg percentages.
Total BSA Burned
0%
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About This Calculator
The Rule of Nines is a rapid method to estimate the total body surface area (TBSA) affected by burns in adults. It divides the body into regions, each representing approximately 9% (or a multiple of 9%) of the total body surface area. This estimation is critical for guiding fluid resuscitation (e.g., Parkland formula) and determining the need for burn center referral.
Formula
Interpretation
| Total BSA Burned | Severity | Management |
|---|---|---|
| < 10% | Minor | Outpatient management possible |
| 10 – 20% | Moderate | Hospital admission recommended |
| > 20% | Major | Burn center referral required |
References
Frequently Asked Questions
When is the Rule of Nines inaccurate?
The adult Rule of Nines is inaccurate in children (who have proportionally larger heads and smaller legs), obese patients, and for patchy or irregular burns. The Lund-Browder chart provides more accurate estimates, especially in pediatric patients.
What percentage of BSA burn requires IV fluid resuscitation?
Burns ≥ 20% TBSA in adults (or ≥ 10% in children) generally require formal IV fluid resuscitation, typically guided by the Parkland formula (4 mL × kg × %TBSA burned of crystalloid in the first 24 hours).
Does the Rule of Nines include first-degree burns?
No. Only second-degree (partial thickness) and third-degree (full thickness) burns are included when calculating TBSA for fluid resuscitation and burn severity assessment. First-degree (superficial) burns are excluded.
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⚠ Medical Disclaimer
This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.