Calculators & Tools

Calcium Correction Calculator

Hypocalcemia / Albumin-Corrected

1 What is the Calcium Correction Calculator?

The Calcium Correction Calculator provides weight-based IV dosing for treating hypocalcaemia, covering both calcium chloride and calcium gluconate, plus a magnesium sulphate dose since low magnesium can cause refractory hypocalcaemia. It calculates calcium chloride 10–20 mg/kg (preferred via central line), calcium gluconate 100 mg/kg (peripheral-vein acceptable), and magnesium sulphate 25–50 mg/kg. The tool also lists the recommended work-up before treatment.

2 When to use it

  • Dosing IV calcium replacement (chloride or gluconate) for a child with symptomatic or significant hypocalcaemia
  • Selecting between calcium chloride (more potent, more sclerosing, central line preferred) and calcium gluconate (peripheral vein acceptable) based on venous access
  • Co-treating magnesium deficiency, since hypomagnesaemia is noted as a cause of refractory hypocalcaemia
  • Directing initial laboratory and imaging work-up (electrolytes, phosphate, magnesium, PTH, vitamin D, urine calcium/creatinine, ECG, wrist X-ray) before or alongside treatment
  • Monitoring for ECG changes such as prolonged QTc associated with hypocalcaemia

3 Formula & method

Calcium chloride 10%: 'CaCl₂ 10–20 mg/kg IV q 10 min, max 500 mg/dose. 10% CaCl₂ = 100 mg/mL = 27.2 mg elemental Ca/mL.' Calcium gluconate 10%: '1 mL/kg IV over 10 minutes (= 100 mg/kg), maximum 40 mL (4 g) per dose. 10% = 100 mg/mL = 9.3 mg elemental calcium/mL.' Magnesium sulphate (if Mg is low): 'MgSO₄ 25–50 mg/kg IV, max 2.5 g/dose. Hypomagnesaemia causes refractory hypocalcaemia — replace Mg first.'

4 Frequently asked questions

What calcium chloride dose does the calculator give?

CaCl₂ 10–20 mg/kg IV every 10 minutes, to a maximum of 500 mg per dose, preferably via central venous line.

What calcium gluconate dose does the calculator give?

Calcium gluconate 10% at 1 mL/kg (100 mg/kg) IV over 10 minutes, to a maximum of 40 mL (4 g) per dose; the app notes it is acceptable via a peripheral vein.

Why does the calculator also include a magnesium dose?

The app explains that hypomagnesaemia causes refractory hypocalcaemia, so magnesium (25–50 mg/kg MgSO₄, max 2.5 g/dose) should be replaced alongside calcium.

What labs and imaging does the app recommend before treating hypocalcaemia?

It recommends a CMP, phosphate, magnesium, PTH, vitamin D, urine calcium/creatinine and protein, ionised calcium, an ECG for prolonged QTc, and a left-wrist X-ray for evidence of rickets.

Why is calcium chloride preferentially given via a central line?

The app notes calcium chloride delivers roughly three times more elemental calcium than calcium gluconate but is also more sclerosing to veins, so a central venous line or large peripheral vein is preferred.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.