Prognostic Nutritional Index (PNI) Calculator

Calculate Onodera's Prognostic Nutritional Index from serum albumin and total lymphocyte count, with the original surgical cut-offs and what they do and do not mean.

Last updated 2 Sep 2026

Prognostic Nutritional Index (PNI)

Albumin + lymphocytes → PNI

Serum albumin (g/dL)An albumin reported in g/L must be divided by 10 first — 36 g/L is 3.6 g/dL.

Total lymphocyte count (cells/mm³)Equivalent to cells/µL. Multiply a count in ×10⁹/L by 1000.

43.5PNIExample

Serum albumin 3.6 g/dL, total lymphocyte count 1,500 cells/mm³

Onodera's formula

PNI = (10 × serum albumin in g/dL) + (0.005 × total lymphocyte count per mm³)

albumin: in g/dL — divide a result reported in g/L by 10 before entering it
total lymphocyte count: absolute lymphocytes per mm³, identical to cells/µL; a count of 1.5 ×10⁹/L is 1,500/mm³
original cut-offs: below 40 anastomosis considered contraindicated, 40 to 45 caution, above 45 regarded as safe

Worked example

Serum albumin 3.6 g/dL, total lymphocyte count 1,500 cells/mm³
Albumin term: 10 × 3.6 = 36.0
Lymphocyte term: 0.005 × 1,500 = 7.5
36.0 + 7.5 = 43.5
Between 40 and 45 → intermediate risk on Onodera's original bands

Onodera's original surgical bands

These are the thresholds from the original 1984 gastrointestinal surgery series and are used here as the reference bands.
PNI	Original interpretation
< 40	Resection with anastomosis considered contraindicated
40 – 45	Increased risk; caution advised
> 45	Resection with anastomosis regarded as safe

Worked components

Albumin dominates the score: a 0.5 g/dL fall costs 5 points, whereas losing 500 lymphocytes/mm³ costs 2.5.
Component	Value entered	Contribution to PNI
Serum albumin	3.6 g/dL	36.0
Total lymphocyte count	1,500/mm³	7.5
Total	—	43.5

What the PNI actually measures

Onodera’s Prognostic Nutritional Index is ten times the serum albumin in g/dL plus five thousandths of the total lymphocyte count per cubic millimetre. It was derived in 1984 in patients undergoing gastrointestinal surgery, where a value below 40 was taken to contraindicate resection with anastomosis, 40 to 45 to indicate caution, and above 45 to be safe. Those original surgical thresholds are the bands shown here.

The unit trap is worth stating plainly, because it produces a wildly wrong answer rather than a slightly wrong one. Albumin must be entered in g/dL. A laboratory reporting 36 g/L means 3.6 g/dL, and entering 36 gives a PNI of 367 rather than 43.5. Similarly, the lymphocyte count is per mm³, which is the same as per µL: a count reported as 1.5 ×10⁹/L is 1,500/mm³.

The index has since been applied to a very large number of oncology cohorts, and the cut-offs used in them vary substantially — values from about 37 to 50 appear in the literature. Each is typically an optimal cut-point derived from the study’s own receiver operating characteristic analysis rather than a prospectively validated threshold, which is why they do not agree and why a PNI should not be compared against a figure taken from an unrelated cohort. The original surgical bands are shown here for that reason.

The deeper limitation is what the two components represent. Albumin is a negative acute-phase reactant and falls with inflammation, capillary leak and fluid shifts independently of nutritional intake, while the lymphocyte count falls with corticosteroids, chemotherapy, radiotherapy, acute infection and HIV. A low PNI therefore reflects inflammatory burden at least as much as nutritional state, which is part of why it predicts outcome so consistently and also why it is a poor guide to whether a patient needs feeding. It is a prognostic marker, not a nutritional assessment tool, and it does not replace a structured assessment such as the Subjective Global Assessment or the GLIM criteria — which require weight loss, reduced intake or muscle mass alongside a disease or inflammation criterion.

Frequently asked questions

How is the Prognostic Nutritional Index calculated?

PNI = 10 × serum albumin in g/dL + 0.005 × total lymphocyte count per mm³. With an albumin of 3.6 g/dL and 1,500 lymphocytes/mm³, the PNI is 36.0 + 7.5 = 43.5.

What are the PNI cut-offs?

Onodera’s original surgical cut-offs were below 40 for contraindicated anastomosis, 40 to 45 for caution, and above 45 for safe. Later oncology studies have used cut-offs anywhere from about 37 to 50, each derived from its own cohort.

My albumin is reported in g/L — what do I enter?

Divide by 10. An albumin of 36 g/L is 3.6 g/dL. Entering the g/L figure directly gives a PNI roughly ten times too high, which is the most common error with this index.

Does a low PNI mean the patient is malnourished?

Not necessarily. Albumin is a negative acute-phase reactant and falls with inflammation regardless of intake, and lymphocytes fall with corticosteroids, chemotherapy and infection, so the index reflects inflammatory burden as much as nutrition.

Can the PNI replace a formal nutritional assessment?

No. It is a prognostic marker rather than an assessment tool and does not substitute for a structured assessment such as the Subjective Global Assessment or the GLIM criteria, which require weight loss, reduced intake or reduced muscle mass alongside a disease or inflammation criterion.

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References

Onodera T, Goseki N, Kosaki G. Prognostic nutritional index in gastrointestinal surgery of malnourished cancer patients [in Japanese]. Nihon Geka Gakkai Zasshi. 1984;85(9):1001–1005.
Cederholm T, Jensen GL, Correia MITD, et al. GLIM criteria for the diagnosis of malnutrition — a consensus report from the global clinical nutrition community. Clin Nutr. 2019;38(1):1–9.
Detsky AS, McLaughlin JR, Baker JP, et al. What is subjective global assessment of nutritional status? JPEN J Parenter Enteral Nutr. 1987;11(1):8–13.

Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.