Steroid (Corticosteroid) Equivalent Dose Calculator

Understanding Corticosteroid Equivalent Doses

Corticosteroids are a class of steroid hormones used widely in medicine to treat inflammatory conditions, autoimmune disorders, adrenal insufficiency, and organ transplant rejection. Because different corticosteroids vary substantially in potency, receptor affinity, duration of action, and metabolic pathways, clinicians frequently need to transition patients from one agent to another — a process called steroid conversion. The Steroid Equivalent Dose Calculator applies a straightforward ratio formula to compute the equipotent dose of any target corticosteroid based on well-established clinical equivalency tables derived from decades of pharmacological research and clinical practice.

The Conversion Formula

The standard formula for converting between corticosteroids is:

D_to = D_from × (E_to / E_from)

Where each variable represents:

• D_to — the equivalent dose of the target corticosteroid, in milligrams
• D_from — the known dose of the source corticosteroid, in milligrams
• E_to — the reference equipotent dose of the target steroid, in milligrams
• E_from — the reference equipotent dose of the source steroid, in milligrams

The formula works by expressing both steroids as a ratio of their pharmacologically established reference doses. A smaller reference equipotent dose reflects higher potency, so the ratio automatically scales the target dose upward or downward to preserve the same anti-inflammatory effect. This approach accounts for the wide range of glucocorticoid potencies observed across the drug class — from relatively weak agents like cortisone to extremely potent compounds like dexamethasone and betamethasone.

Equipotent Dose Reference Values

The following anti-inflammatory equivalency values are sourced from authoritative clinical references including MDCalc's Steroid Conversion Calculator and the UpToDate glucocorticoid equivalency table:

• Cortisone: 25 mg (relative potency 0.8)
• Hydrocortisone: 20 mg (relative potency 1.0 — the reference compound)
• Prednisone: 5 mg (relative potency 4)
• Prednisolone: 5 mg (relative potency 4)
• Methylprednisolone: 4 mg (relative potency 5)
• Triamcinolone: 4 mg (relative potency 5)
• Dexamethasone: 0.75 mg (relative potency approximately 26–27)
• Betamethasone: 0.6 mg (relative potency approximately 33)

Worked Examples

A patient currently receiving prednisone 20 mg/day must transition to methylprednisolone due to a formulation change. Applying the formula with E_from = 5 mg (prednisone) and E_to = 4 mg (methylprednisolone):

D_to = 20 × (4 / 5) = 16 mg methylprednisolone per day

In a second scenario, a patient on hydrocortisone 60 mg/day requires conversion to dexamethasone for its lack of mineralocorticoid activity:

D_to = 60 × (0.75 / 20) = 2.25 mg dexamethasone per day

A third example illustrates conversion in the opposite direction: converting dexamethasone 2 mg/day to prednisone for chronic therapy:

D_to = 2 × (5 / 0.75) = 13.3 mg prednisone per day

These calculations illustrate how the formula captures the wide potency differences across the corticosteroid class. Dexamethasone is approximately 26 times more potent than hydrocortisone on a milligram basis, making precise arithmetic essential to avoid under- or over-dosing.

Clinical Applications

• Adrenal insufficiency management: Transitioning between oral and parenteral corticosteroids during stress dosing, illness, or hospitalization, as detailed in the Merck Manual on Adrenal Insufficiency.
• Immunosuppression tapering: Switching agents during long-term therapy for autoimmune diseases such as systemic lupus erythematosus or inflammatory bowel disease.
• Formulary substitution: Replacing an unavailable corticosteroid with a therapeutically equivalent alternative during drug shortages or insurance formulary changes.
• Perioperative bridging: Adjusting corticosteroid regimens around surgical procedures when oral absorption is unreliable and intravenous alternatives are required.

Important Limitations

These equivalency values apply exclusively to glucocorticoid (anti-inflammatory) potency. They do not account for mineralocorticoid activity, which governs sodium and fluid retention and varies substantially across agents. Hydrocortisone and cortisone carry significant mineralocorticoid effects, while dexamethasone and betamethasone carry virtually none. Differences in plasma half-life, route of administration, bioavailability, and tissue-level metabolism may further affect clinical outcomes beyond what the formula captures. Individual patient factors including age, renal and hepatic function, body composition, and genetic polymorphisms in glucocorticoid receptor expression can influence actual clinical response. All computed equivalent doses should be reviewed and approved by a licensed healthcare provider before any change to a medication regimen is implemented.