Electrolytes & Minerals

Calcium, Total (Ca²⁺)

Normal range 8.6–10.2 mg/dL (2.15–2.55 mmol/L SI). Specimen: Serum.

Also known as: serum calcium.

8.6–10.2 mg/dLCritical: read below

Reference range

Conventionalmg/dL

8.610.2

SImmol/L

2.152.55

Specimen	Serum
Conventional range	8.6–10.2 mg/dL
SI range	2.15–2.55 mmol/L
Conversion factor	×0.25 (conventional → SI)
Critical value	< 6.0 or > 13.0 mg/dL
Panel	Electrolytes & Minerals

Convert any Calcium, Total (Ca²⁺) result between units on the unit converter.

What is the normal range for Calcium, Total (Ca²⁺)?

The standard teaching reference range for Calcium, Total (Ca²⁺) is 8.6–10.2 mg/dL in conventional units, or 2.15–2.55 mmol/L in SI units. This value is measured in serum.

A commonly taught critical (panic) value is < 6.0 or > 13.0 mg/dL. Critical results are reported to the provider immediately under your facility's policy.

Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population — always use the range printed on the actual result.

Above the range

Common causes of a high Calcium, Total (Ca²⁺)

Hyperparathyroidism
Malignancy
Excess vitamin D
Prolonged immobilization

Below the range

Common causes of a low Calcium, Total (Ca²⁺)

Hypoparathyroidism
Vitamin D deficiency
Chronic kidney disease
Low albumin (total only)

At the bedside

Nursing considerations

Correct total calcium for albumin, or measure ionized calcium.
Check Chvostek and Trousseau signs and watch for tetany when low.

Study aid

Your notes on Calcium, Total (Ca²⁺)

Your notes

Same panel

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Anion Gap8–16 mEq/L Bicarbonate (CO₂ content)22–29 mEq/L Calcium, Ionized4.6–5.3 mg/dL Chloride (Cl⁻)98–106 mEq/L Magnesium (Mg²⁺)1.6–2.6 mg/dL Phosphate (Phosphorus)2.5–4.5 mg/dL