Health calculators

Sofa Score Calculator

Updated Jul 28, 2026 By Jehan Wadia
Enter the most abnormal (worst) value for each parameter over the past 24-hour period.
Global unit system
Switches PaO₂, MAP, bilirubin and creatinine units and converts the entered values. Individual selectors below override this.

1. Respiration

Score: — / 4
Device estimates: nasal cannula 24–44%, simple mask 35–50%, venturi 24–60%, non-rebreather 60–90%.
P/F Ratio: —
Is the patient on mechanical ventilation or CPAP?

2. Coagulation

Score: — / 4

3. Liver (Bilirubin)

Score: — / 4

4. Cardiovascular

Score: — / 4
Is the patient receiving vasopressors?

5. Neurological (GCS)

Score: — / 4
If the patient is on sedatives or paralytic agents, estimate the GCS as if they were off sedation.

6. Renal

Score: — / 4
A numeric entry automatically sets the category below.
Creatinine score: — | Urine output score: — → Renal score: —
Total SOFA Score
/ 24
Complete all fields to see your total SOFA score

Enter the worst 24-hour value for each of the six organ systems.

Per Sepsis-3 criteria, sepsis is defined as a SOFA score increase of ≥2 points from baseline in the setting of suspected infection, associated with organ dysfunction.
Per-Organ Sub-Score Breakdown
SOFA sub-score by organ system
Organ systemValue(s) enteredScore
Respiration
Coagulation
Liver
Cardiovascular
Neurological
Renal
Total
Step-by-Step Solution
Mortality Risk by Maximum SOFA Score
Estimated hospital mortality by maximum SOFA score
Max SOFA scoreEstimated hospital mortality
0–6 <10%
7–9 15–20%
10–12 40–50%
13–14 50–60%
15 >80%
16–24 >90%
Serial Score Trend Interpretation
Mortality by SOFA trend over first 48 hours
SOFA trend (first 48 h of ICU admission)Estimated mortality
Increasing>50%
Unchanged27–35%
Decreasing<27%
Serial SOFA scoring over 48 hours provides greater prognostic value than a single-timepoint score.
Estimated Hospital Mortality by SOFA Score
The highlighted bar marks the band containing the current total score. The table to the left is the text alternative for this chart.

Introduction

The SOFA Score Calculator works out the Sequential Organ Failure Assessment score. Doctors and nurses use this score in the ICU to see how well six organ systems are working in a very sick patient. Each system gets 0 to 4 points. Add them up and you get a total from 0 to 24. A higher score means more organ failure and a higher risk of death.

This tool scores all six systems for you:

  • Lungs – PaO₂/FiO₂ ratio and use of a ventilator or CPAP
  • Blood clotting – platelet count
  • Liver – total bilirubin
  • Heart and blood pressureMAP and vasopressor doses
  • Brain – Glasgow Coma Scale (GCS)
  • Kidneys – creatinine and 24-hour urine output

Enter the worst value for each item from the past 24 hours. You can use US or SI units, and the calculator converts them for you. You get each organ sub-score, the total score, an estimated hospital death risk, and a step-by-step view of the math.

The SOFA score is also part of the Sepsis-3 rules. A rise of 2 or more points from a patient's baseline, along with a suspected infection, points to sepsis. Checking the score again over the first 48 hours tells you more than one score alone. Use this calculator to support your judgment, not to replace it.

How to use our SOFA Score Calculator

Enter the worst lab and vital sign values from the last 24 hours for six organ systems. The calculator gives you a score from 0 to 4 for each organ, a total SOFA score out of 24, your mortality risk band, and a step-by-step breakdown.

Global unit system: Pick US or SI units. This switches the units for PaO₂, MAP, bilirubin, and creatinine, and converts any numbers you already typed. You can still change each unit on its own.

PaO₂: Type the arterial oxygen level from the blood gas. Choose mmHg, kPa, Pascal, cmH₂O, or torr.

FiO₂: Type how much oxygen the patient is breathing. Choose percent, a fraction, or litres per minute. Room air is 21%.

Mechanical ventilation or CPAP: Pick Yes or No. Scores of 3 and 4 need breathing support, so a "No" answer caps the lung score at 2.

Platelet count: Type the lowest platelet count. Choose ×10³/µL, ×10⁹/L, or cells/µL. For neutrophil-based counts, see the ANC Calculator.

Total bilirubin: Type the highest bilirubin. Choose mg/dL, µmol/L, or mg%. Bilirubin also feeds into the Child-Pugh Calculator and the MELD Calculator for liver disease staging.

Mean arterial pressure (MAP): Type the lowest MAP. Choose mmHg, kPa, or cmH₂O. If you only have systolic and diastolic readings, work it out first with the MAP Calculator.

Vasopressors: Pick Yes or No. Picking Yes opens boxes for drug doses.

Dopamine and dobutamine: Type the dose in mcg/kg/min. Any dobutamine dose scores 2 points. To set the pump rate for these drips, the IV Infusion Rate Calculator and Infusion Drip Calculator can help.

Epinephrine and norepinephrine: Type the dose and pick mcg/kg/min or mcg/min.

Patient weight: Type the weight in kg or lbs. This is needed only if you enter a flat mcg/min dose, so it can be changed to mcg/kg/min. Use the Kg to Lbs Calculator if you need to swap units, or the Adjusted Body Weight Calculator for dosing in obese patients.

Glasgow Coma Scale (GCS): Pick the total GCS from 3 to 15. If the patient is sedated or paralyzed, guess the GCS as if they were off the drugs.

Serum creatinine: Type the highest creatinine. Choose mg/dL, µmol/L, or mmol/L. Related kidney tools include the GFR Calculator, the Creatinine Clearance Calculator, and the BUN Creatinine Ratio Calculator.

24-hour urine output: Type the total urine in mL or L per day, or pick a range from the drop-down list. The calculator uses whichever renal score is higher: creatinine or urine output. To check mL/kg/hr, use the Urine Output Calculator.

Load Example Patient: Click this to fill in sample values and see how the tool works. Click Reset twice to clear everything.

What Is the SOFA Score?

SOFA stands for Sequential Organ Failure Assessment. It is a score doctors use in the intensive care unit (ICU) to see how many organs are failing and how badly. Each of six organ systems gets 0 to 4 points. Higher points mean worse organ function. All six scores add up to a total from 0 to 24.

The Six Organ Systems

  • Lungs (respiration): uses the PaO₂/FiO₂ ratio. This compares oxygen in the blood to oxygen the patient breathes in. Scores of 3 and 4 need a ventilator or CPAP.
  • Blood clotting (coagulation): uses the platelet count. Low platelets mean more bleeding risk. Patients on anticoagulation may also be tracked with the Heparin Drip Calculator.
  • Liver: uses total bilirubin. A sick liver lets bilirubin build up, which can turn skin and eyes yellow. The AST ALT Ratio Calculator and MELD Na Calculator add more detail on liver injury.
  • Heart and blood flow (cardiovascular): uses mean arterial pressure (MAP) and any drugs used to raise blood pressure, like norepinephrine or dopamine. Higher drug doses mean more points. For output-based measures, see the Cardiac Index Calculator and the Fick Cardiac Output Calculator.
  • Brain (neurological): uses the Glasgow Coma Scale (GCS), which rates how awake and aware a patient is. In alcohol withdrawal, pair this with the CIWA Calculator.
  • Kidneys (renal): uses creatinine in the blood and how much urine is made in a day. The worse of the two scores counts. The FENa Calculator can help sort out the cause of low urine output.

Why the Score Matters

The SOFA score helps the care team judge how sick a patient is and guess the risk of dying in the hospital. A score of 6 or less links to a low risk. A score of 15 or more links to a very high risk. But the score is a guide, not a promise. It does not decide care by itself.

Checking the Score Over Time

One score tells you about one moment. Repeating the score each day tells you more. If the score goes up in the first 48 hours in the ICU, the risk of death is higher. If it stays the same or goes down, the outlook is better. That is why the word "sequential" is in the name.

SOFA and Sepsis

The Sepsis-3 guidelines use SOFA to define sepsis. If a patient has a suspected infection and the SOFA score rises by 2 points or more from their baseline, that counts as sepsis. Patients with no known organ problems are assumed to start at a baseline of 0.

How to Use It Right

Use the worst value for each item from the last 24 hours. If the patient is sedated or paralyzed, estimate the GCS as if the drugs were not given. Drug doses count only if they ran for at least one hour, and they are measured in mcg/kg/min. Because of this, weight matters when a dose is written as mcg/min.

Limits to Keep in Mind

SOFA was built for adults in the ICU. It is not made for children, and it was not designed to predict how one single person will do. Long-term illness, like chronic kidney disease or liver disease, can raise the score even when the patient is not getting worse. Always read the score along with the full clinical picture.

Related Clinical Calculators

Other bedside tools that pair well with SOFA scoring include the Anion Gap Calculator and Serum Osmolality Calculator for metabolic status, the Corrected Calcium Calculator and Ionized Calcium Calculator for electrolytes, the QTc Calculator and CHA₂DS₂-VASc Calculator for cardiac risk, and the BSA Calculator for weight-based dosing and indexed measurements.


Formulas used

PaO₂/FiO₂ (P/F) ratio
\text{P/F} = \frac{\text{PaO}_2\ (\mathrm{mmHg})}{\text{FiO}_2\ (\text{fraction})}
FiO₂ estimated from oxygen flow rate (L/min)
\text{FiO}_2 = \frac{\min\left(100,\ 21 + 4 \times \text{flow}_{\mathrm{L/min}}\right)}{100}
Weight-normalised vasopressor dose (from mcg/min)
\text{Dose}\ (\mu g/kg/min) = \frac{\text{Dose}\ (\mu g/min)}{\text{Weight}\ (\mathrm{kg})}
Cardiovascular sub-score (highest applicable agent/MAP criterion)
S_{\text{cardio}} = \max\left(S_{\text{dopamine}},\ S_{\text{dobutamine}},\ S_{\text{epinephrine}},\ S_{\text{norepinephrine}},\ S_{\text{MAP}}\right)
Renal sub-score (higher of creatinine and urine output)
S_{\text{renal}} = \max\left(S_{\text{creatinine}},\ S_{\text{urine output}}\right)
Total SOFA score
\text{SOFA} = S_{\text{resp}} + S_{\text{coag}} + S_{\text{liver}} + S_{\text{cardio}} + S_{\text{neuro}} + S_{\text{renal}}
Unit conversions (bilirubin and creatinine)
\text{Bili}_{\mathrm{mg/dL}} = \frac{\text{Bili}_{\mu\mathrm{mol/L}}}{17.1}, \qquad \text{Cr}_{\mathrm{mg/dL}} = \frac{\text{Cr}_{\mu\mathrm{mol/L}}}{88.4}
Pressure unit conversion to mmHg (PaO₂, MAP)
P_{\mathrm{mmHg}} = P_{\mathrm{kPa}} \times 7.50062 = P_{\mathrm{cmH_2O}} \times 0.7355592

Frequently asked questions

What do I do if I do not have a PaO2 from a blood gas?

The lung part of the SOFA score needs PaO₂ from an arterial blood gas. Without it, the calculator cannot give a respiration score, so the total stays blank.

SpO₂ from a pulse oximeter is not part of the official score. Draw a blood gas if you can. Some ICUs use an SpO₂/FiO₂ ratio instead, but that is a different scoring method.

Why is my respiration score stuck at 2 when the P/F ratio is very low?

Scores of 3 and 4 only count if the patient is on a ventilator or CPAP. If you answer No to breathing support, the calculator caps the lung score at 2, even when the P/F ratio is under 100.

Change the answer to Yes if the patient is on a vent or CPAP, and the score will move up.

How does the tool change oxygen litres per minute into FiO2?

It uses this rule: FiO₂% = 21 + (4 × litres per minute), with a top limit of 100%.

So 4 L/min becomes about 37%. This is only a rough guess for nasal cannula. If the patient is on a ventilator, type the set FiO₂ instead.

Do I have to enter the patient's weight?

Only if you type an epinephrine or norepinephrine dose in mcg/min. SOFA scores drug doses in mcg/kg/min, so the tool needs weight to convert.

If every dose is already in mcg/kg/min, you can leave weight blank.

The patient is on two vasopressors. Are the points added together?

No. The calculator uses the highest single score, not the sum. If norepinephrine gives 4 points and dobutamine gives 2, the cardiovascular score is 4.

The green "Score driven by" line shows which drug and dose set the score.

What about vasopressin, phenylephrine, or angiotensin II?

The original SOFA score only lists dopamine, dobutamine, epinephrine, and norepinephrine, so those are the only boxes here.

If your patient is on another vasopressor, write it in the chart and use your clinical judgment. Do not guess a dose for a drug that is not listed.

Why does the kidney score use the higher of creatinine and urine output?

SOFA scores the kidneys by whichever finding is worse. That way a patient who is barely making urine still scores high even if creatinine has not risen yet.

Example: creatinine 2.1 mg/dL gives 2 points, urine output 150 mL/day gives 4 points, so the renal score is 4.

How do I score the kidneys if the patient is on dialysis or CRRT?

The original SOFA score has no dialysis rule, so this calculator scores only the numbers you type. Dialysis can lower creatinine and make urine output near zero, which can be misleading.

Many ICU teams give 4 renal points when a patient needs dialysis for acute kidney failure. Note the dialysis in the chart either way.

Why is my total score showing a dash instead of a number?

A required field is empty or invalid. The total needs all of these: PaO₂, FiO₂, platelets, bilirubin, MAP, GCS, creatinine, and urine output.

Look for the red text under each box. Single organ sub-scores still show while you fill in the rest.

Is qSOFA the same thing as this score?

No. qSOFA is a quick 3-item bedside screen: breathing rate 22 or more, systolic blood pressure 100 mmHg or less, and changed mental state. It scores 0 to 3 and needs no labs.

The full SOFA score uses labs and drug doses and scores 0 to 24. qSOFA screens for risk; SOFA measures organ failure.

Can I use this calculator for children?

No. SOFA was built and tested in adults. Normal creatinine, blood pressure, and platelet values change with age, so adult cut-offs do not fit kids.

Pediatric units use a separate score called pSOFA, which has age-based cut-offs.

What counts as the patient's baseline SOFA score?

The baseline is the score the patient would have had before this illness started.

If the patient has no known long-term organ problem, use a baseline of 0. If they have chronic kidney or liver disease, their baseline is already above 0, so compare against that.

What is a normal P/F ratio?

A healthy adult breathing room air usually has a P/F ratio above 400.

  • 300 or less: mild lung injury
  • 200 or less: moderate
  • 100 or less: severe

The calculator shows the ratio in a blue box right under the FiO₂ box.

Does this calculator save or send patient data?

No. All math runs inside your browser. Nothing is stored, saved, or sent anywhere. Reloading the page clears every value.

What does the red bar on the mortality chart mean?

The red bar marks the score band your patient's current total falls into. All other bars stay dark blue.

The same information appears in the table beside the chart, with a "Current score" tag on the matching row.

I only have systolic and diastolic blood pressure. What should I enter for MAP?

Work out MAP first with this formula: MAP = (systolic + 2 × diastolic) ÷ 3.

For 100/60, MAP = (100 + 120) ÷ 3 = about 73 mmHg. Then type that number in the MAP box.

My lab reports platelets as x10⁹/L. Do I need to convert them?

No. Just pick ×10⁹/L from the drop-down. That unit is the same number as ×10³/µL, so 90 stays 90.

Pick cells/µL only if your value is written in full, like 90,000.

Does a SOFA score of 2 mean the patient has sepsis?

No, not on its own. Sepsis-3 needs two things: a suspected or proven infection, and a rise of 2 or more SOFA points above the patient's baseline.

A total of 2 from long-term kidney disease with no infection is not sepsis.

The patient is sedated and intubated. How do I score GCS?

Estimate the GCS as if the sedation were not running. Use the last exam before sedation started, or a sedation break if one was done.

Do not score a low GCS just because the drugs make the patient unresponsive, because that inflates the score.

Can I use the mortality numbers to decide one patient's care?

No. SOFA was made to describe organ failure in groups of ICU patients, not to predict what happens to one person.

Use it to track trends and support your judgment. Treatment choices must rest on the full clinical picture.

How is SOFA different from APACHE II?

APACHE II is scored once, in the first 24 hours after ICU admission, and includes age and chronic health problems. It predicts death risk on arrival.

SOFA can be repeated every day and only measures how organs are working right now. That makes it better for tracking change over time.

What happens if I switch between US and SI units after typing values?

The calculator converts the numbers you already typed. Switching to SI changes PaO₂ and MAP to kPa, and bilirubin and creatinine to µmol/L, with the values updated to match.

You can still set any one field to a different unit afterward.