The rule of nines estimates how much of an adult’s skin is burned by assigning each body region 9% or a multiple of 9: head 9%, each arm 9%, each leg 18%, front and back of the trunk 18% each, and perineum 1%. Only partial- and full-thickness burns count. That total body surface area (TBSA) drives the Parkland formula for IV fluids.
Key takeaways
- Adult map: head 9%, each arm 9%, each leg 18%, front trunk 18%, back trunk 18%, perineum 1%.
- Young children: under age 1 the head is 18% and each leg 14%; each year, take 1% off the head and add 0.5% to each leg.
- Superficial burns don’t count. Only partial- and full-thickness burns go into TBSA.
- Parkland: 4 mL × kg × %TBSA over 24 hours from the time of the burn, half in the first 8 hours.
- It’s a starting rate. The American Burn Association’s 2024 guideline recommends starting adults at 2 mL/kg/%TBSA, and rates are titrated to urine output.
What the Rule of Nines Estimates (and What It Doesn’t)
The rule gives a fast estimate of the percentage of total body surface area burned (%TBSA). That number guides IV fluids, severity and burn center referral. StatPearls traces it to Pulaski and Tennison in 1949 and to A.B. Wallace, who published it in 1951 and whose name it often carries. You’ll also see it written as the rule of 9’s.
It doesn’t measure depth, and it is an estimate. StatPearls notes it is most accurate between 10 and 80 kg and that, at 25% to 35% TBSA, estimates ran about 20% higher than computer mapping. The fluid formula multiplies that error, and StatPearls’ fluid resuscitation review notes that many patients reach burn centers over-hydrated, partly from overestimated burn size.
For small or scattered burns, use the palmar method. The American Burn Association treats the patient’s palm as about 1% of TBSA and notes some settings use palm plus fingers (about 0.8% to 1%). Use the patient’s hand, not yours.
Adult Rule of Nines Chart
In adults, each region is 9% or a multiple of 9, with front and back counted separately, so you can add partial areas such as the front of one leg (9%).
| Region | Front | Back | Total |
|---|---|---|---|
| Head and neck | 4.5% | 4.5% | 9% |
| Each arm | 4.5% | 4.5% | 9% |
| Trunk | 18% (chest 9%, abdomen 9%) | 18% | 36% |
| Each leg | 9% | 9% | 18% |
| Perineum | – | – | 1% |
Always check the back. New South Wales’ Agency for Clinical Innovation tells clinicians to expose the whole body and calculate front and back surfaces. StatPearls adds that burns can deepen or spread over time, so recalculate when the wound changes.
Pediatric Rule of Nines and the Lund-Browder Chart
Children need a different map because their heads are larger and their legs smaller. In the pediatric rule of nines used by New South Wales’ Agency for Clinical Innovation for children under 9, the first-year values are head 18%, each leg 14%, each arm 9%, and front and back trunk 18% each.
For every year of age, take 1% from the head and add 0.5% to each leg. A 4-year-old’s head is 14% and each leg 16%; by age 9 the child reaches adult values.
The Lund-Browder chart is more precise, and both the American Burn Association and the Merck Manual point to it for children. It adjusts the head, thighs and lower legs by age:
| Age | Head | One thigh | One lower leg |
|---|---|---|---|
| Birth | 19% | 5.5% | 5% |
| 1 year | 17% | 6.5% | 5% |
| 5 years | 13% | 8% | 5.5% |
| 10 years | 11% | 8.5% | 6% |
| 15 years | 9% | 9% | 6.5% |
StatPearls also describes a proposed rule of eights for children under 10 kg (head 20%, trunk 32%, each leg 16%, each arm 8%). Learn the chart your pediatric course and clinical site use.
Which Burns Count Toward TBSA
Count partial-thickness and full-thickness burns; leave superficial burns out. A sunburn-type burn that is red, dry and unblistered adds nothing to TBSA, even over a large area.
Superficial vs partial vs full thickness
| Depth | What you see | Healing | In TBSA? |
|---|---|---|---|
| Superficial | Dry, red, blanches easily, no blisters | 5–10 days | No |
| Superficial partial | Moist, red, blisters, very painful | 2–3 weeks | Yes |
| Deep partial | Drier, paler, blanches less, less pain | Slower, scars | Yes |
| Full-thickness | Dry, leathery, white, brown or black; no pinprick sensation | Over 8 weeks; surgery | Yes |
If a burn could be either deep partial or full thickness, Merck advises treating it as full thickness; the difference can take 24 to 48 hours to show.
Parkland Formula Step by Step
The Parkland formula estimates 24-hour lactated Ringer’s as 4 mL × kg × %TBSA, with half given in the first 8 hours after the burn and half over the next 16. StatPearls’ Parkland Formula review applies it to adults with burns over 20% TBSA and children over 10% (its fluid review says 10% to 15%, varying by institution).
- Estimate %TBSA from partial- and full-thickness burns only.
- Convert weight to kg (pounds ÷ 2.2); see our dosage calculation guide.
- Multiply 4 mL × kg × %TBSA for the 24-hour total.
- Halve it. The first half is due within 8 hours of the injury, not of arrival.
- Subtract prehospital fluid from the first half; divide the rest by the hours left in that window.
- Divide the second half by 16 for the hourly rate.
- Titrate to urine output as ordered and record intake, output and vital signs hourly.
These calculations are study examples. Real burn resuscitation follows your facility’s protocol and the provider’s orders; the formula only sets a starting rate that the team adjusts hour by hour. Never change an infusion rate based on your own calculation.
The American Burn Association’s 2024 guideline for adults with burns of 20% TBSA or more recommends starting at 2 mL/kg/%TBSA instead of 4 to reduce fluid volume (an AAFP summary explains the aim is avoiding edema-related complications). Merck and StatPearls still present Parkland at 4 mL, so use 4 when a question names Parkland, or the multiplier the question or order gives.
For children, StatPearls describes 3 mL/kg/%TBSA (some protocols use 4) plus separate maintenance fluid, because small glycogen stores raise hypoglycemia risk. Merck notes large saline volumes can cause hyperchloremic acidosis, which is why lactated Ringer’s is preferred; our fluid and electrolyte guide explains the background.
Three Worked Examples (Adult, Child, Mixed-Depth)
Work each on paper first. These are study examples using Parkland 4 mL unless stated.
Example 1: Adult, 45% TBSA
An 80 kg man has partial-thickness burns to the front of his trunk, his entire left arm and the front of both legs. Fluids start at the time of injury.
- TBSA: 18 + 9 + 9 + 9 = 45%.
- 24 hours: 4 × 80 × 45 = 14,400 mL.
- First 8 hours: 7,200 ÷ 8 = 900 mL/h; next 16 hours: 7,200 ÷ 16 = 450 mL/h.
- Urine goal: 0.5 × 80 = 40 mL/h.
At the ABA’s 2 mL start, the rates halve to 450 then 225 mL/h. Had he arrived 2 hours late without fluids, the 7,200 mL would run over the 6 hours left: 1,200 mL/h.
Example 2: Child, 24% TBSA
A 2-year-old weighing 12 kg has partial-thickness scalds over the entire right arm and right leg.
- At age 2 the leg is 14 + 0.5 + 0.5 = 15%, so TBSA = 9 + 15 = 24% (the adult chart would say 27%).
- At 3 mL: 3 × 12 × 24 = 864 mL; 432 ÷ 8 = 54 mL/h, then 432 ÷ 16 = 27 mL/h, plus ordered maintenance fluid.
- Urine goal under 30 kg: 1 × 12 = 12 mL/h.
At 4 mL the total is 1,152 mL: 72 mL/h, then 36 mL/h.
Example 3: Mixed depth, late arrival
A 60 kg woman arrives 2 hours after a kitchen fire with a deep partial-thickness burn to her entire right arm, a full-thickness burn to the front of her right leg, blistered burns across her chest, and red, unblistered skin on her face and front of her left arm. Paramedics gave 1,000 mL of lactated Ringer’s.
- TBSA: arm 9 + front leg 9 + chest 9 = 27%; the superficial face and arm add 0.
- 24 hours: 4 × 60 × 27 = 6,480 mL; first half 3,240 mL.
- 3,240 − 1,000 = 2,240 mL over the 6 hours left = about 373 mL/h.
- Next 16 hours: 3,240 ÷ 16 = 202.5 mL/h. Urine goal: 30 mL/h.
Counting the red face and arm would give 36% and 8,640 mL, about 2.2 liters too much.
A 50 kg adult has partial-thickness burns over the whole back of the trunk and the backs of both legs, with fluids starting at the time of injury. Answer: 18 + 9 + 9 = 36%; 4 × 50 × 36 = 7,200 mL; 450 mL/h for 8 hours, then 225 mL/h; urine goal 25 mL/h.
Burn questions mix the map, the math and the priorities. These medical-surgical test banks and critical care test banks are self-quizzing aids written to one textbook edition, not your instructor’s exam. Publishers write them mainly for instructors and some programs restrict them, so check your honor code, ask your instructor, and skip them if your program prohibits them.
- Lewis’s Medical-Surgical Nursing, 12th edition test bank — for the 12th edition (Chapter 26 is Burns); Elsevier’s 13th edition (2026) is newer and not matched.
- Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th edition test bank — for the 15th; the 16th edition (October 2025) is newer and not matched.
- Urden’s Critical Care Nursing, 9th edition test bank — for ICU courses; the 9th edition has a Burns chapter.
Each test bank is matched to one edition and ISBN-13. Check the number on your book before you buy.
Priority Nursing Care in the Emergent Burn Phase
Airway first, then circulation and fluids, then pain and infection. StatPearls stresses that severely burned patients are trauma patients first. In burns nursing, that means the primary survey comes before burn sizing.
Airway
Watch for inhalation injury: singed facial or nasal hair, soot-stained sputum, burns around the mouth, breathing symptoms, or confinement in a burning space. Merck advises considering early intubation when these appear and treating suspected smoke inhalation with 100% oxygen. StatPearls’ thermal burn review notes carboxyhemoglobin’s half-life is 4 hours or less on 100% oxygen, so a low level drawn later doesn’t rule out inhalation injury.
Fluids and urine output
Expect two large-bore IVs through unburned skin when possible and a urinary catheter for hourly output. StatPearls’ fluid review gives adult goals of 30 to 50 mL/h (0.5 to 1 mL/kg/h), 1 mL/kg/h for children under 30 kg, and about 1 mL/kg/h with rhabdomyolysis, and advises against boluses without evidence of hypovolemia.
Over-resuscitation (fluid creep) causes pulmonary edema and abdominal or limb compartment syndrome, and abdominal compartment syndrome can itself lower urine output. Check circumferential limb burns for pain out of proportion, tingling, coolness and weak pulses.
Pain and infection
Merck notes opioids should be given IV, sometimes in large doses; OpenStax’s Medical-Surgical Nursing suggests premedicating at least 30 minutes before dressing changes. Merck also notes fever and a raised white count are common without infection, so watch trends such as feeding intolerance, falling platelets or rising glucose. Keep the patient warm, use aseptic technique and check tetanus status.
When to call a burn center
The ABA’s referral guidelines call for immediate burn center consultation for full-thickness burns, partial-thickness burns of 10% TBSA or more, deep partial- or full-thickness burns of the face, hands, feet, genitalia, perineum or joints, suspected inhalation injury, chemical injuries and high-voltage electrical injuries.
Frequently asked questions
What is the rule of nines?
It is a quick way to estimate the percentage of body surface burned. In adults, the head is 9%, each arm 9%, each leg 18%, the front and back of the trunk 18% each, and the perineum 1%. Add up the partial- and full-thickness areas to guide fluids and referral.
Why is the rule of nines different for children?
Young children have larger heads and shorter legs. In the pediatric version, an infant’s head is 18% and each leg 14%; each year, the head drops 1% and each leg gains 0.5% until adult values at age 9. The Lund-Browder chart is more precise.
Do superficial burns count in TBSA?
No. Superficial burns are red, dry and blanch easily without blisters, like a typical sunburn, and they are left out. Only partial-thickness burns (blistered, moist, pale or mottled) and full-thickness burns (leathery, white, brown or black) count. Leaving superficial areas out keeps the fluid calculation from overestimating.
How do you calculate fluids with the Parkland formula?
Multiply 4 mL by weight in kilograms and %TBSA for the 24-hour volume of lactated Ringer’s. Give half within 8 hours of the injury and half over the next 16, subtracting prehospital fluid. It is a starting rate adjusted under the provider’s orders.
What urine output shows adequate burn resuscitation?
StatPearls gives adults 0.5 to 1 mL/kg/h (about 30 to 50 mL/h) and children under 30 kg about 1 mL/kg/h. Higher goals near 1 mL/kg/h are used for rhabdomyolysis. Output below target suggests under-resuscitation, while spreading edema despite large volumes suggests fluid creep. Your facility’s protocol and the provider’s orders set the exact goal.
Bottom line
Learn the adult map, add the pediatric adjustment, and practice Parkland math until halving, timing and subtracting prehospital fluid feel automatic. Then quiz yourself on your textbook’s burn chapter, using our med-surg study guide and how to use a nursing test bank with nursing test banks matched to your edition.
Sources & further reading
- StatPearls (Europe PMC) — Rule of Nines, updated 2024
- StatPearls (Europe PMC) — Parkland Formula, updated 2023
- StatPearls (Europe PMC) — Burn Fluid Resuscitation, updated 2025
- Journal of Burn Care & Research — ABA Clinical Practice Guidelines on Burn Shock Resuscitation (2024)
- American Burn Association — Guidelines for Burn Patient Referral
- Merck Manual Professional Version — Burns
- NSW Agency for Clinical Innovation — Burn assessment (paediatric)
