Parkland formula explained: how to estimate burn fluid needs for a 90 kg patient with 40% TBSA

Burn care in the field isn’t just about stopping the burn—it’s about keeping the whole system perfusing long enough for healing to begin. When big burns meet big needs, the Parkland formula becomes a practical compass. It translates a rough view of injury into a real plan for fluids in the first 24 hours. Let me walk you through what that looks like for a 90 kg person with a 40% burn, and then we’ll connect the dots to field realities.

What the Parkland formula actually tells us

The Parkland formula is straightforward in concept: you need a certain amount of fluid based on body weight and how much skin was burned. The classic statement is:

Total fluid in the first 24 hours = 4 ml × body weight (kg) × TBSA burned (%)

Here’s the math for our example:

• Weight = 90 kg

• TBSA burned = 40%

Total fluid = 4 ml/kg × 90 × 40 = 14,400 ml over the first 24 hours

That 14.4 liters isn’t all dumped at once. It’s a schedule:

• Half of that volume should be given in the first 8 hours after the burn

• The remaining half over the next 16 hours

So, in our case:

• First 8 hours: 7,200 ml total → about 900 ml per hour

• Next 16 hours: 7,200 ml total → about 450 ml per hour

That’s a simple, clean plan you can translate into a real, time-bound infusion. And yes, you’d typically use a crystalloid like Lactated Ringer’s (LR) in burn resuscitation, unless a different fluid is dictated by context or comorbidities.

A quick pause on the numbers you might see

If you average the total 14,400 ml over the full 24 hours, you get 600 ml/hour. That sounds neat, but it’s a different way of looking at the same obligation. The Parkland approach emphasizes the time split—eight hours for the first big push, then the rest over the subsequent hours. In the field, many clinicians plan the “first eight” push to jump-start perfusion and then adjust as fluid losses, urine output, and blood pressure shift.

Sometimes you’ll see the proposed rate rounded or presented in a more simplified way. You might encounter a ballpark number around 500 ml/hr in some quick references or teaching scenarios. The reality on the ground, though, is that the 8-hour/16-hour split matters. The aim is to prevent under-resuscitation early (poor perfusion) and avoid excessive fluid that could worsen edema or tissue damage later. So the exact hourly rate you start with isn’t a rigid target; it’s a starting point you adjust based on how the patient responds.

Putting this into the field context

Tactical and austere environments present real constraints. You won’t always have continuous monitoring bells and whistles. Still, the guiding principle remains: re-establish adequate circulation, monitor urine output, and watch vital signs closely. A pragmatic approach looks like this:

• Start with a fluid plan based on weight and burn size (the Parkland framework).

• Target urine output as a guide: in adults, roughly 0.5 mL/kg per hour is a common target (so for a 90 kg adult, about 45 mL/hour). If urine output falls short, you revisit the infusion rate and volume.

• Be mindful of time: the first eight hours are critical for restoring capillary perfusion. If you’re delayed delivering fluids, you’ll have to compensate promptly once care is on scene.

• Adjust in response to the patient: blood pressure trends, capillary refill, heart rate, and mental status all matter. If signs point to hypoperfusion despite fluids, you’ll need to reassess.

Why this matters for battlefield care

Burn injuries are blunt force trauma on the body’s fluid balance. The skin’s barrier is gone, so fluid shifts, evaporative losses, and inflammatory responses pull fluid away from the bloodstream. The Parkland plan isn’t about vanity fluid numbers; it’s about giving the heart and kidneys enough volume to keep tissues oxygenated while the body begins repair. In a tactical setting, that translates to:

• A clear plan that can be executed with limited equipment

• A focus on early, decisive management to prevent shock

• A structure for titration—fluids up or down based on tangible feedback (urine output, hemodynamics)

• A reminder to balance resuscitation with other priorities (airway, bleeding control, pain management)

A few practical notes you’ll likely encounter

• The fluid choice matters: LR is a common starting fluid for burn resuscitation because it’s closer to blood’s own electrolyte balance than normal saline. In some situations, other crystalloids may be used, but LR remains a staple in many guidelines.

• Time zero is a moving target: the eight-hour window is counted from the time of burn injury, not from when you start seeing the patient. If you arrive late, you still aim to deliver the initial half of the fluid within the eight-hour span as best you can, given the circumstances.

• Not one-size-fits-all: underlying health, age, comorbidities, and the exact nature of the burn all influence how you adjust. If a patient has heart or kidney issues, the plan will look different, and close monitoring becomes even more critical.

• Field realities can change the math: equipment limitations, competing injuries, and transport times all influence how aggressively you push fluids. The core idea—support perfusion while avoiding over-resuscitation—guides every decision.

How to keep the flow simple when you need to think fast

If you’re teaching someone new—or refreshing your own recall—try this quick mental model:

• Step 1: Identify weight and %TBSA burned

• Step 2: Calculate total fluid for 24 hours: 4 ml × weight × TBSA

• Step 3: Split the schedule into two parts: 8 hours (half) and 16 hours (the other half)

• Step 4: Translate into hourly targets for the first phase (about 900 ml/hr), then for the second phase (about 450 ml/hr)

• Step 5: Monitor urine output and vital signs; adjust as needed

A friendly caveat and a takeaway

One thing to keep in mind: the exact hourly rate isn’t the whole story. It’s a scaffold for real-time decisions. You’ll tweak it based on how the patient responds because no two burns are exactly alike. The important takeaway is this: early, sustained fluid resuscitation guided by weight and burn size, plus careful monitoring, gives the body the best chance to fight through the initial shock and begin healing.

Grabbing hold of the bigger picture

Burn resuscitation is a blend of science and judgment. The Parkland framework gives you a concrete starting point, but the art is in how you apply it under pressure—given the tools at hand, the patient’s trajectory, and the pace of care you can sustain. That balance—structure plus adaptability—is what separates good field clinicians from great ones.

If you’re studying or practicing this material, you’ll find that fluid management for burns sits at an interesting crossroad: you have a clear protocol, yet you must read the patient’s signals like a weather pattern. A rising heart rate, a stubbornly rising pulse pressure, a drop in urine output—these aren’t just numbers; they’re messages from the body about what it needs right now.

Takeaways to carry forward

• For a 90 kg person with a 40% burn, the Parkland calculation gives 14,400 ml in 24 hours.

• The classic distribution is 7,200 ml in the first 8 hours (about 900 ml/hour) and 7,200 ml over the next 16 hours (about 450 ml/hour).

• In practice, clinicians titrate based on urine output (target roughly 0.5 mL/kg/hour) and other vital signs.

• The key is to start promptly and adjust as you go, keeping perfusion stable while avoiding fluid overload.

• In field settings, use LR when available, monitor closely, and stay flexible with the schedule as patient and scene demands shift.

If you ever find yourself in a scenario where you’re weighing these numbers aloud, take a breath and recall the core idea: fluids are the bridge to life during the early hours after a burn. Build that bridge firmly, then watch for the signs that tell you whether to widen it, narrow it, or hold steady. In the end, the goal is simple: keep the patient moving toward stability and healing, even when the environment isn’t.

A small glossary for quick recall

• TBSA: Total body surface area percent burned

• LR: Lactated Ringer’s solution

• Hemodynamics: The movement of blood through the body and how it’s measured by cues like blood pressure and heart rate

• Urine output: A practical, real-time clue about perfusion and fluid status

In the end, the math isn’t just math. It’s a language that helps you translate injury into care, order into action, and urgency into life-saving decisions. That balance—clear numbers, watched responses, and the grit to adapt—defines effective burn resuscitation in demanding environments.