Steroid Conversion Calculator
Enter your current corticosteroid, dose in milligrams, and the target steroid. The calculator applies the standard anti-inflammatory potency ratios to give you the equipotent dose, plus a comparison of glucocorticoid potency, mineralocorticoid activity, and biological half-life. All conversions are for systemic oral or intravenous administration only and are for clinical reference.
Formula
Worked example
Converting prednisone 10 mg to methylprednisolone: prednisone potency = 4, methylprednisolone potency = 5. Hydrocortisone equivalent = 10 mg x 4 = 40 mg. Methylprednisolone dose = 40 mg / 5 = 8 mg. This result is confirmed by the equivalent-dose table (prednisone 5 mg = methylprednisolone 4 mg, so 10 mg = 8 mg).
How corticosteroid conversion works
All glucocorticoids (corticosteroids) exert their anti-inflammatory effects through the same glucocorticoid receptor, but they differ widely in potency - that is, the dose needed to produce a given effect. Hydrocortisone is used as the reference standard with a potency of 1. Prednisone and prednisolone are four times as potent, so 5 mg of prednisone replaces 20 mg of hydrocortisone. Dexamethasone and betamethasone are 25 times as potent, making 0.8 mg equivalent to the same 20 mg hydrocortisone reference dose. To convert from one steroid to another, multiply the current dose by the current potency to get the hydrocortisone equivalent, then divide that result by the target steroid's potency.
Glucocorticoid vs. mineralocorticoid activity
Corticosteroids also differ in how much they activate the mineralocorticoid receptor, which governs sodium and water retention, potassium excretion, and blood pressure. Hydrocortisone and cortisone have significant mineralocorticoid activity; prednisone and prednisolone have moderate activity; and methylprednisolone, triamcinolone, dexamethasone, and betamethasone have little to none. When switching between classes, particularly from a short-acting agent with high mineralocorticoid activity to a long-acting agent with none, watch for electrolyte and blood pressure changes. The equipotency conversions in this calculator are for anti-inflammatory effect only; mineralocorticoid replacement (for adrenal insufficiency) requires separate consideration.
Duration of action and dosing frequency
Short-acting steroids such as hydrocortisone and cortisone have a biological half-life of roughly 8-12 hours and are given two to three times daily for replacement therapy. Intermediate-acting agents - prednisone, prednisolone, methylprednisolone, and triamcinolone - last 12-36 hours and are usually given once or twice daily. Long-acting agents - dexamethasone and betamethasone - have biological half-lives of 36-54 hours and are often given once daily or even every other day for inflammatory conditions. When the computed equivalent dose lands you in a different duration class, the dosing frequency usually needs to change as well. The equivalent dose calculation does not do that adjustment automatically.
Limitations and clinical cautions
These conversions are population-based estimates and do not account for individual pharmacogenetic variation, route differences beyond oral vs IV, adrenal suppression history, or pediatric dosing, which requires weight-based calculations. They are intended as a clinical reference guide, not a replacement for clinical judgment. Abrupt switching between steroids or stopping long courses without tapering can precipitate adrenal crisis. For inhaled, topical, intra-articular, or epidural administration, separate bioavailability and potency data apply and this calculator does not cover those routes. Always verify critical steroid conversions with a clinical pharmacist.
Corticosteroid equivalency reference table
| Steroid | Equivalent dose (mg) | Anti-inflammatory potency | Mineralocorticoid potency | Duration |
|---|---|---|---|---|
| Hydrocortisone | 20 | 1 | 1 | Short |
| Cortisone | 25 | 0.8 | 0.8 | Short |
| Prednisone | 5 | 4 | 0.6 | Intermediate |
| Prednisolone | 5 | 4 | 0.6 | Intermediate |
| Methylprednisolone | 4 | 5 | 0.25 | Intermediate |
| Triamcinolone | 4 | 5 | 0 | Intermediate |
| Dexamethasone | 0.8 | 25 | 0 | Long |
| Betamethasone | 0.8 | 25 | 0 | Long |
Standard anti-inflammatory potency ratios and equivalent doses for systemic oral or IV administration. Hydrocortisone (HC = 1) is the reference compound. Duration: Short = 8-12 h, Intermediate = 12-36 h, Long = 36-54 h.
Frequently asked questions
What is an equipotent corticosteroid dose?
An equipotent dose is the amount of one steroid that produces the same anti-inflammatory effect as a given dose of another. All conversions use hydrocortisone as the reference: hydrocortisone 20 mg is the baseline. Prednisone 5 mg is equipotent to that 20 mg because prednisone is 4 times as potent per milligram. Dexamethasone 0.8 mg is also equipotent because it is 25 times as potent.
Do these conversions apply to inhaled or topical steroids?
No. This calculator covers systemic oral and intravenous corticosteroids only. Inhaled steroids (fluticasone, budesonide, beclomethasone) and topical steroids have different potency scales and local-to-systemic bioavailability ratios that make direct comparison with systemic doses unreliable. Use inhaled or topical potency tables specific to those routes.
Why do prednisone and prednisolone have the same equivalent dose?
Prednisone is a prodrug that the liver converts to prednisolone, the active form. They have essentially the same anti-inflammatory potency once absorbed. In patients with significant liver disease, prednisolone is preferred because conversion from prednisone may be impaired.
Why does methylprednisolone have no mineralocorticoid activity?
The addition of a methyl group at position 6 of prednisolone increases glucocorticoid potency and eliminates mineralocorticoid binding. This makes methylprednisolone a better choice when you want potent anti-inflammation without salt and water retention, such as in high-dose IV pulse therapy for acute inflammatory or autoimmune conditions.
Should I adjust dosing frequency when switching steroids?
Yes. The equivalent dose you calculate tells you how many milligrams to give per dose, but it does not change how many times per day you need to dose. If you switch from hydrocortisone (short-acting, given 2-3 times daily) to prednisone (intermediate-acting, given once daily), you need to recalculate the daily total and give it in fewer, larger doses. Failing to adjust frequency can result in over- or under-treatment.
What is adrenal suppression and why does it matter for switching steroids?
Long-term steroid use suppresses the hypothalamic-pituitary-adrenal axis, meaning the body stops producing cortisol on its own. If steroids are stopped abruptly or the dose is reduced too quickly, the adrenal glands may not respond fast enough, potentially causing adrenal crisis. When switching or tapering, follow a gradual reduction schedule under medical supervision, particularly after high-dose or long-duration therapy.