About the Ranson Criteria Calculator
Ranson’s criteria are one of the oldest and best-known prognostic scores for acute pancreatitis. John Ranson identified 11 objective signs in his 1974 series — five measured on admission (age, white cell count, glucose, LDH and AST) and six measured during the first 48 hours (fall in hematocrit, rise in BUN, calcium, arterial oxygen, base deficit and fluid sequestration). Each sign present scores one point.
The original criteria were derived mainly in alcohol-related pancreatitis. In 1982 Ranson published a modified 10-item version for gallstone (biliary) pancreatitis with higher admission thresholds, a smaller BUN rise, a larger base deficit and a smaller fluid sequestration, and without the PaO₂ criterion. Pick the etiology and this calculator applies the matching thresholds automatically.
Enter the admission labs, then turn on the 48-hour section once those results are available. A score of 3 or more is the classic marker of severe pancreatitis. The mortality bands come from the original adult series and are much higher than modern outcomes; newer tools such as BISAP and the revised Atlanta classification are often preferred, so use the score alongside clinical judgment.
With the default inputs, the ranson score is 4. Change any value above to recalculate instantly.
How to use the ranson criteria calculator
- 1Choose gallstone or non-gallstone pancreatitis to set the thresholds.
- 2Enter age and the admission WBC, glucose, LDH and AST.
- 3After 48 hours, switch on the 48-hour criteria and enter the changes and lowest values.
- 4Read the total score, the severity band and which criteria were met.
- 5Interpret the result alongside imaging, organ function and newer scores.
Formula and method
Each criterion is a yes/no threshold and scores one point when it is crossed. Non-gallstone (original 1974) admission criteria: age > 55, WBC > 16,000/mm³, glucose > 200 mg/dL, LDH > 350 U/L, AST > 250 U/L. 48-hour criteria: hematocrit fall > 10 points, BUN rise > 5 mg/dL, calcium < 8 mg/dL, PaO₂ < 60 mmHg, base deficit > 4 mEq/L and fluid sequestration > 6 L.
Gallstone (1982) admission criteria: age > 70, WBC > 18,000/mm³, glucose > 220 mg/dL, LDH > 400 U/L, AST > 250 U/L. 48-hour criteria: hematocrit fall > 10 points, BUN rise > 2 mg/dL, calcium < 8 mg/dL, base deficit > 5 mEq/L and fluid sequestration > 4 L. A total of 3 or more predicts severe disease; reported mortality is about 0–3% for 0–2 points, 15% for 3–4, 40% for 5–6 and close to 100% for 7 or more.
- WBC
- White blood cell count
- LDH
- Lactate dehydrogenase
- AST
- Aspartate aminotransferase
- BUN
- Blood urea nitrogen
- PaO₂
- Arterial partial pressure of oxygen
Worked examples
Alcohol-related pancreatitis, full 48-hour score
Age 60 (> 55), WBC 17,000 (> 16,000) and LDH 400 (> 350) give three admission points; glucose 180 and AST 120 are below threshold. Over 48 hours only the calcium of 7.6 mg/dL (< 8) scores, for a total of 4 — severe, with about 15% mortality in Ranson’s series.
Same labs, gallstone thresholds
With the gallstone thresholds, age 60 (≤ 70), WBC 17,000 (≤ 18,000) and LDH 400 (not > 400) no longer score. In the 48-hour set, the BUN rise of 3 mg/dL now exceeds 2 and calcium 7.6 is below 8, giving 2 points — predicted mild disease.
Admission only, older patient
All five non-gallstone admission criteria are met (age 72, WBC 19,000, glucose 250, LDH 500, AST 300), so the admission score alone is 5. The 48-hour criteria are not yet included, so the final score can only stay the same or go up.
Frequently asked questions
What is a high Ranson score?+
A Ranson score of 3 or more indicates severe acute pancreatitis. In the original series, mortality was about 0–3% with 0–2 points, around 15% with 3–4, around 40% with 5–6 and close to 100% with 7 or more.
Why does Ranson need 48 hours?+
Six of the original 11 criteria (five of the 10 gallstone criteria) measure how the illness evolves — hematocrit fall, BUN rise, calcium, PaO₂, base deficit and fluid sequestration — so the complete score is only available 48 hours after admission.
What is different in gallstone pancreatitis?+
Ranson’s 1982 modification for biliary pancreatitis uses higher admission cut-offs (age > 70, WBC > 18,000, glucose > 220, LDH > 400), a BUN rise > 2 mg/dL, base deficit > 5 mEq/L, fluid sequestration > 4 L, and drops the PaO₂ criterion, giving 10 items.
Is Ranson still used?+
It remains widely taught and quoted, but it cannot be completed until 48 hours, and its mortality figures come from the 1970s. Many clinicians now favour BISAP, persistent SIRS, APACHE II and the revised Atlanta classification for organ failure.
How is fluid sequestration estimated?+
It is the net fluid balance over the first 48 hours: total intravenous and oral fluid given minus measured losses such as urine, nasogastric output and drains. A large positive balance reflects fluid lost into the inflamed pancreas and tissues.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.
Sources
- Ranson JH et al. Prognostic signs and the role of operative management in acute pancreatitis. Surg Gynecol Obstet 1974 (PubMed)
- Ranson JH. Etiological and prognostic factors in human acute pancreatitis: a review. Am J Gastroenterol 1982 (PubMed)
- A Clinical Overview of Acute and Chronic Pancreatitis (gallstone-modified Ranson thresholds) — Cureus 2021, PMC
- Utility of Ranson score, CTSI and CRP in acute pancreatitis (mortality bands) — PMC