Potassium Deficit Calculator
Estimates total body potassium deficit in hypokalaemia. Used to guide IV/oral potassium replacement.
Score interpretation
Serum potassium within normal range (3.5–5.0 mmol/L).
→ No replacement required. Reassess if symptomatic.
Mild hypokalaemia. Approximate deficit 100–200 mmol.
→ Oral potassium replacement (potassium chloride 40–80 mmol/day). Identify and treat cause. Repeat level in 24–48 hours.
Moderate hypokalaemia. Estimated deficit 200–400 mmol.
→ Oral or IV potassium (IV rate ≤20 mmol/hour via central line; ≤10 mmol/hour peripherally). Cardiac monitoring if symptomatic. Co-replace magnesium.
Severe hypokalaemia (<2.5 mmol/L). Estimated deficit >400 mmol. Risk of arrhythmia.
→ Urgent IV replacement (cardiac monitored environment). IV K⁺ 20 mmol/hour via central line. Continuous ECG monitoring. Replace magnesium concurrently. Senior review.
Interpretation bands for the K⁺ Deficit. Apply clinical judgement and local guidance.
References
- Weiner ID, Wingo CS. Hypokalemia — consequences, causes, and correction. J Am Soc Nephrol. 1997;8(7):1179-1188.
- NICE Clinical Guideline. Intravenous fluid therapy in adults in hospital (CG174). 2013.
Related
Curated clinical cross-links plus same-class fallbacks.
- Potassium chloride · Potassium replacement
- Potassium chloride with potassium bicarbonate · Effervescent potassium replacement
- Potassium Chloride (IV) · Electrolyte — Potassium Supplement
- Amiloride hydrochloride · Potassium-sparing diuretic (epithelial Na+ channel blocker)
- Co-amilofruse · Loop diuretic + potassium-sparing
- Co-amilozide · Thiazide + potassium-sparing
- Hyperkalaemia Management · UK Kidney Association Guidelines 2020; NICE CKD Guidelines
- Rhabdomyolysis · Renal Association 2018; UpToDate 2024
- Hypocalcaemia (Adult) · Society for Endocrinology
- SIADH (Endocrine Perspective) · European Hyponatraemia Guidelines 2014
- Hepatorenal Syndrome · EASL 2018; ICA 2015
- Acute Kidney Injury (AKI) · KDIGO 2012 / NICE AKI 2019
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.