Goal
Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians.
CURB-65 Pneumonia Severity Score Calculator
Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians.
Key facts
- What it does
- Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians.
- Formula
CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5.- You enter
- Age · New confusion documented · Blood urea above 7 mmol/L · Respiratory rate · Systolic blood pressure · Diastolic blood pressure
- Worked example
- CURB-65 = 0 points for the supplied example inputs.
A clearer path to an answer
From your question to a useful result
This page keeps the calculation transparent: define the goal, enter the matching values, inspect the method, and decide what the result means in your situation.
Inputs
Age · New confusion documented · Blood urea above 7 mmol/L · Respiratory rate · Systolic blood pressure · Diastolic blood pressure
Method
CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5.
Next step
Calculate, review the assumptions below, then compare a related tool when the decision needs more context.
CURB-65 Pneumonia Severity Score Calculator
Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians.
Open the CURB-65 Pneumonia Severity Score Calculator pageMore health tools
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Result
Enter your values above and choose Calculate to see the result here.
Calculation map
Follow the path from input to answer
01
Inputs (6)
- Age Ready
- New confusion documented Ready
- Blood urea above 7 mmol/L Ready
- Respiratory rate Ready
- +2 more inputs
02
Formula
CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5.
Bounded, transparent calculation
03
Result
- Calculate to preview the result.
Recent runs
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Formula, assumptions, and example
Formula: CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5.
The calculator makes the five CURB-65 points visible and derives respiratory-rate, blood-pressure, and age points from numeric inputs. It is a pneumonia severity aid, not a diagnosis, admission order, or substitute for oxygenation and examination.
- A clinician has assessed a possible or confirmed community-acquired pneumonia context before applying the score.
- Urea is entered as the score’s threshold status in mmol/L; blood urea nitrogen in another unit needs a validated conversion before use.
- Respiratory rate contributes one point at 30 breaths per minute or higher.
- Low blood pressure contributes one point when systolic pressure is below 90 or diastolic pressure is 60 or lower.
- Age contributes one point at 65 years or older.
- The score does not include oxygen saturation, work of breathing, imaging, comorbidities, sepsis, social support, or response to treatment.
- The result does not choose outpatient care, ward admission, intensive care, antibiotics, or fluid treatment.
- Confusion, severe breathlessness, blue lips, low blood pressure, or rapid deterioration require urgent medical assessment regardless of score.
Worked example: CURB-65 = 0 points for the supplied example inputs.
Displayed input contract
- Age · minimum 18 · maximum 120
- New confusion documented · 2 choices
- Blood urea above 7 mmol/L · 2 choices
- Respiratory rate · minimum 1 · maximum 100
- Systolic blood pressure · minimum 40 · maximum 300
- Diastolic blood pressure · minimum 20 · maximum 200
The displayed limits are checked before the handler runs. Model-specific domain checks may also reject impossible or non-finite inputs.
Methodology: This calculator follows the WorldCalculate input, formula, precision, and boundary policy. Read the official methodology.
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Answer-first guide
How to use the CURB-65 Pneumonia Severity Score Calculator for a real question
Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians. Start with one clearly defined goal, enter values in the units shown, and keep the result attached to the assumptions below.
What this answers
This tool is useful when your question includes CURB-65 calculator, pneumonia severity score, CURB65 score. It returns the outputs declared in the calculator contract rather than a live quote, approval, diagnosis, or professional sign-off.
What you enter
Age · New confusion documented · Blood urea above 7 mmol/L · Respiratory rate · Systolic blood pressure · Diastolic blood pressure. Keep the same time period, unit system, and currency wherever the form requires comparable values.
How to check it
Run the worked example first, compare its output with the page's example, then change one input at a time. This makes an unexpected result easier to trace to a unit, boundary, or assumption.
Three checks before you rely on the answer
- Match the question. Confirm that the result means the quantity you need, not a similar-sounding percentage, balance, rate, or estimate.
- Match the inputs. Use the requested units and period, and read each hint before replacing the example values with your own.
- Read the boundary. Review the assumptions and limits. A clinician has assessed a possible or confirmed community-acquired pneumonia context before applying the score.
Need a wider view? Browse Health Calculators or compare the related tools below. The WorldCalculate methodology explains how formulas, examples, limits, and revisions are reviewed.
How to use the CURB-65 Pneumonia Severity Score Calculator
- Enter Age (years).
- Enter New confusion documented.
- Enter Blood urea above 7 mmol/L.
- Enter Respiratory rate (breaths/min).
- Enter Systolic blood pressure (mmHg).
- Enter Diastolic blood pressure (mmHg).
- Choose Calculate and read the result panel.
- Use Download PDF or Download Word to save a result sheet.
Formula
CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5.
The calculator makes the five CURB-65 points visible and derives respiratory-rate, blood-pressure, and age points from numeric inputs. It is a pneumonia severity aid, not a diagnosis, admission order, or substitute for oxygenation and examination.
Worked example
CURB-65 = 0 points for the supplied example inputs.
Assumptions and limits
- A clinician has assessed a possible or confirmed community-acquired pneumonia context before applying the score.
- Urea is entered as the score’s threshold status in mmol/L; blood urea nitrogen in another unit needs a validated conversion before use.
- Respiratory rate contributes one point at 30 breaths per minute or higher.
- Low blood pressure contributes one point when systolic pressure is below 90 or diastolic pressure is 60 or lower.
- Age contributes one point at 65 years or older.
- The score does not include oxygen saturation, work of breathing, imaging, comorbidities, sepsis, social support, or response to treatment.
- The result does not choose outpatient care, ward admission, intensive care, antibiotics, or fluid treatment.
- Confusion, severe breathlessness, blue lips, low blood pressure, or rapid deterioration require urgent medical assessment regardless of score.
Who uses this calculator?
- Students learning the CURB-65 components
- Clinicians checking a documented pneumonia score
- Readers learning why pneumonia severity scores need broader assessment
When is it useful?
- Add the five CURB-65 criteria with thresholds shown explicitly.
- Show how respiratory rate, pressure, and age create points.
- Keep a severity score separate from disposition and treatment decisions.
Context and background
How health estimates should be read
Health calculators use measurements and population-level relationships to produce screening or planning estimates. They describe the supplied model; they do not diagnose, prescribe, or replace clinical judgment.
Many familiar health formulas began as practical ways to summarize measurements. Their limits matter as much as their output because individual bodies, medications, conditions, and professional standards vary.
Research and review
How this guide was researched
Researched by Hassan ALRowaie, Founder and editorial researcher at WorldCalculate.
This guide follows the live calculator's declared inputs, formula, worked example, assumptions, validation boundaries, and source-backed methodology. The review date describes editorial review of the calculator explanation; it is not a promise that external facts or rates remain current.
CURB-65 summarizes five findings used in some pneumonia severity pathways: confusion, urea, respiratory rate, blood pressure, and age. WorldCalculate makes the thresholds auditable while emphasizing that pneumonia care also depends on oxygenation, examination, imaging, comorbidities, and how quickly someone is changing.
What CURB-65 represents
CURB-65 is a five-point severity score associated with community-acquired pneumonia assessment. Each letter corresponds to a clinical finding, and the 65 refers to the age threshold.
It is a support tool for an assessed patient, not a way to diagnose pneumonia from numbers alone.
The five criteria
The displayed criteria are new confusion, urea above 7 mmol/L, respiratory rate at least 30 per minute, low blood pressure, and age at least 65 years.
The blood-pressure component gives a point when systolic pressure is below 90 or diastolic pressure is 60 or lower.
How to use the calculator
Enter the values recorded during the relevant assessment. Use the score’s unit for urea or convert it with a validated clinical method before selecting the threshold.
The page displays the pressure and respiratory-rate points separately so a boundary can be checked.
Worked example
A 50-year-old person with no new confusion, urea not above the threshold, respiratory rate 18, and blood pressure 120/75 has zero points in the arithmetic example.
This example does not mean that pneumonia is absent or that no care is needed.
Why oxygenation still matters
CURB-65 does not include oxygen saturation, oxygen requirement, work of breathing, or gas exchange. A person can be seriously unwell with a modest score.
Look at the whole patient and the local emergency or respiratory pathway.
Disposition is not a calculator output
The score may inform a discussion about treatment location in a validated pathway, but it does not choose admission, discharge, ward care, or intensive care by itself.
Comorbidities, frailty, social support, imaging, sepsis, and response to initial treatment can change the decision.
Unit and measurement pitfalls
Urea and blood urea nitrogen are related but not the same numeric unit. Confirm the laboratory units before deciding whether the threshold is crossed.
Respiratory rate should be counted rather than estimated from a hurried glance, and blood pressure should be interpreted with the measurement conditions.
Urgent pneumonia symptoms
Severe breathlessness, blue or grey lips, new confusion, fainting, very low blood pressure, inability to stay awake, or rapidly worsening symptoms require urgent local care.
Do not wait for the score to reach a particular value before calling emergency services.
FAQs
Does CURB-65 diagnose pneumonia? No. Does zero mean safe to stay home? No. Can it choose antibiotics or admission? No; it is one input to a qualified clinical assessment.
Frequently asked questions
What is the CURB-65 Pneumonia Severity Score Calculator?
Calculate the five-point CURB-65 structure from confusion, urea, respiratory rate, blood pressure, and age while keeping disposition decisions with clinicians.
What is the formula for the CURB-65 Pneumonia Severity Score Calculator?
CURB-65 = new confusion (1) + urea >7 mmol/L (1) + respiratory rate ≥30/min (1) + systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg (1) + age ≥65 years (1). Maximum 5. The calculator makes the five CURB-65 points visible and derives respiratory-rate, blood-pressure, and age points from numeric inputs. It is a pneumonia severity aid, not a diagnosis, admission order, or substitute for oxygenation and examination.
What do I need to use this calculator?
Enter Age, New confusion documented, Blood urea above 7 mmol/L, Respiratory rate, Systolic blood pressure, Diastolic blood pressure, then choose Calculate.
What are the limits of this calculator?
A clinician has assessed a possible or confirmed community-acquired pneumonia context before applying the score. Urea is entered as the score’s threshold status in mmol/L; blood urea nitrogen in another unit needs a validated conversion before use. Respiratory rate contributes one point at 30 breaths per minute or higher. Low blood pressure contributes one point when systolic pressure is below 90 or diastolic pressure is 60 or lower. Age contributes one point at 65 years or older. The score does not include oxygen saturation, work of breathing, imaging, comorbidities, sepsis, social support, or response to treatment. The result does not choose outpatient care, ward admission, intensive care, antibiotics, or fluid treatment. Confusion, severe breathlessness, blue lips, low blood pressure, or rapid deterioration require urgent medical assessment regardless of score.
Methodology
This calculator is part of the WorldCalculate library. Its formula, example, assumptions, input bounds, and output formatting follow the official methodology.
Use this calculator as part of a bigger plan
These WorldCalculate collections connect this tool with related questions while keeping each calculation separate and transparent.