Burn TBSA Calculator – Adult Rule of Nines

This adult estimate divides the body into fixed anterior and posterior head-and-neck, arm, trunk, and leg segments, plus the perineum/genitalia. The listed segment weights total 100%, and this page lets each fixed segment be partly affected.

Sources: [1, 2, 4]

Record superficial partial-thickness, deep partial-thickness, and full-thickness areas. Exclude superficial erythema and epidermal or older first-degree burns. This page cannot determine or verify burn depth.

Sources: [2, 3]

The classic adult proportions assign separate fixed weights to front and back surfaces. Recording them separately allows an estimate when only part of one side of a body region is affected.

Sources: [1, 2]

For each selected segment, enter the percentage of that listed segment affected. A value of 100% means the entire listed segment; the calculator multiplies that percentage by the segment’s fixed TBSA weight.

Sources: [1, 4]

No. Burn TBSA is the proportion of skin surface involved in qualifying burn depth. Ordinary body surface area is a height-and-weight estimate used for different purposes.

Sources: [2, 4]

Lund–Browder charts use age-related body proportions and can be more precise for children and some complex patterns. This page calculates only the classic adult Rule of Nines estimate.

Sources: [4, 10]

The Rule of Nines is a quick approximation based on standard adult proportions. Obesity, unusual body proportions, and small scattered or irregular burns can make those fixed proportions less accurate.

Sources: [8, 9, 10]

A palmar method can be useful for small, scattered, or irregular areas when an appropriate local protocol is used. Published conventions vary between the palm alone and the palmar surface including fingers, so the local definition matters. It is a different method and is not calculated on this page.

Sources: [4, 10]

Current ABA guidance includes partial-thickness burns at least 10% TBSA among referral considerations, but depth, special sites, mechanism, inhalation injury, and other factors matter. This page does not make a referral decision.

Sources: [3]

The 2024 ABA burn-shock resuscitation guideline applies to adults with burns at least 20% TBSA and recommends initiating resuscitation at 2 mL/kg/%TBSA to reduce fluid volumes, followed by clinical titration. That is not a dynamic severity category, and this calculator does not calculate that current starting approach or prescribe fluids.

Sources: [5]

Yes. Face, hands, feet, genitalia/perineum, joints, circumferential injuries, inhalation injury, chemical injury, and electrical injury can need specialist assessment even with a small calculated area.

Sources: [3, 5]

Early boundaries and depth may be difficult to define and can change over time. Reassessment may change the documented qualifying area without implying that this calculator diagnosed the burn.

Sources: [3, 4, 10]