Estimated blood volume + max allowable blood loss

Estimated blood volume (weight*EBV factor) and maximum allowable blood loss from starting and minimum acceptable hematocrit.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Weight
70 kg
Patient type
Child / adult male (75)
Starting hematocrit
45 %
Minimum acceptable hematocrit
30 %

Result: Estimated blood volume 5250 mL; maximum allowable blood loss 1750 mL.

The tool opens with these values already filled in. Replace them with your own.

What you enter

  • Weight
  • Patient type (EBV factor, mL/kg)
  • Starting hematocrit
  • Minimum acceptable hematocrit
How this is calculated

Gross JB. Estimating allowable blood loss: corrected for dilution. Anesthesiology. 1983;58(3):277-280. MABL = EBV x (start Hct - min Hct) / start Hct; the paper takes the estimated blood volume as an input and publishes no per-kilogram table, so the factor is the reader's to choose. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.