Bicarbonate Deficit (Approximate)

Deficit (mEq) ≈ 0.5 × weight (kg) × (target HCO3 − current HCO3); floored at zero.

Calculator

Body weight (kg)

Current serum bicarbonate (mEq/L)

Target bicarbonate (mEq/L)

Default target 24 mEq/L is a common teaching anchor—actual goals are diagnosis- and patient-specific. Other models use different distribution volumes (e.g., 0.3 × kg).

Estimated deficit

How it works

What this tool does

It multiplies total body weight by half the bicarbonate gap as a simplified teaching estimate sometimes used when discussing alkali replacement.

Formula (this page)

Deficit (mEq) = max(0, 0.5 × weight_kg × (HCO3_target − HCO3_current))

References

Adrogue HJ, Madias NE. Management of life-threatening acid-base disorders. N Engl J Med. 1998;338(26):107-111. (Context for cautious bicarbonate use.)

Dosing & care

Teaching cautions

Overly rapid correction risks overshoot alkalosis, hypokalemia, and ionized hypocalcemia.
In organic acidoses (e.g., ketoacidosis), treat the underlying disorder; bicarbonate use is selective and guideline-driven.

Limitations

Real distribution volume varies with acid-base disorder type, renal function, and timing; this page is not a replacement for ICU pharmacy or nephrology dosing software.

Replacement principles (teaching)

Many protocols replace only a fraction of the calculated deficit per interval with repeat labs.
Replete potassium and monitor calcium when giving bicarbonate in high-risk settings.
Do not base bolus therapy on this screen alone—use team-based decisions and monitoring.

Educational tool only—not for diagnosis or treatment decisions.