Calculate equivalent corticosteroid doses and convert between prednisone, dexamethasone, methylprednisolone, hydrocortisone, and other steroids.
Steroid Conversion Formula
The calculator converts a dose of one corticosteroid into the dose of another that has roughly the same systemic glucocorticoid (anti-inflammatory) effect. It uses each drug’s standard equivalent dose:
D2 = D1 * (E2 / E1)
Variables:
- D2 is the equivalent dose of the target steroid, in mg
- D1 is the dose of the current steroid you enter, in mg
- E1 is the standard equivalent dose of the current steroid (for example 5 mg for prednisone)
- E2 is the standard equivalent dose of the target steroid (for example 0.75 mg for dexamethasone)
To express any dose as a common reference, the calculator also reports the hydrocortisone-equivalent burden and the prednisone-equivalent:
HCE = D1 * (20 / E1) PE = D1 * (5 / E1)
HCE is the total daily amount of hydrocortisone that carries the same glucocorticoid effect, and PE is the same idea expressed as prednisone. Alongside the dose, the calculator reports a relative salt-retention index, found by multiplying the dose by the drug’s mineralocorticoid potency, so you can see whether a switch raises or lowers fluid-retention risk. Pick “Convert one steroid to another” to move between two named drugs, or “Show equivalent doses of all steroids” to see one dose mapped across every agent at once. The optional doses-per-day field adds the total daily burden.
Corticosteroid Equivalent Doses and Potency
These are the standard equivalent doses used for systemic (oral or IV) conversion, with relative anti-inflammatory potency, relative salt-retaining (mineralocorticoid) potency, and duration of action. Higher anti-inflammatory potency means a smaller dose does the same job; higher mineralocorticoid potency means more sodium and water retention.
| Steroid | Equivalent dose (mg) | Anti-inflammatory potency | Salt-retaining potency | Duration |
|---|---|---|---|---|
| Hydrocortisone | 20 | 1 | 1 | Short (8-12 h) |
| Cortisone acetate | 25 | 0.8 | 0.8 | Short (8-12 h) |
| Prednisone | 5 | 4 | 0.8 | Intermediate (12-36 h) |
| Prednisolone | 5 | 4 | 0.8 | Intermediate (12-36 h) |
| Methylprednisolone | 4 | 5 | 0.5 | Intermediate (12-36 h) |
| Triamcinolone | 4 | 5 | 0 | Intermediate (12-36 h) |
| Dexamethasone | 0.75 | 25 to 30 | 0 | Long (36-54 h) |
| Betamethasone | 0.6 | 25 to 30 | 0 | Long (36-54 h) |
| Deflazacort | 6 | 3 to 4 | 0 | Intermediate (12-36 h) |
Duration of action changes how often a dose is given and how much it suppresses the adrenal axis. This table pairs each duration class with a typical dosing pattern and what to do when a conversion moves across classes. This adjustment step is easy to miss, because matching the glucocorticoid dose does not match the frequency.
| Duration class | Examples | Biologic half-life | Typical dosing | When converting |
|---|---|---|---|---|
| Short | Hydrocortisone, cortisone | 8 to 12 h | 2 to 3 times daily | Most salt retention; split doses |
| Intermediate | Prednisone, methylprednisolone | 12 to 36 h | Once or twice daily | Moderate salt retention |
| Long | Dexamethasone, betamethasone | 36 to 54 h | Once daily or less | No salt retention; give less often |
Burden also sets context. A hydrocortisone-equivalent of about 15 to 25 mg per day matches normal physiologic replacement, roughly what the adrenal glands make. Above that range the dose is pharmacologic, and sustained pharmacologic doses beyond about three weeks call for a taper rather than an abrupt stop, because the adrenal axis is suppressed.
Example Problems
Example 1: Convert prednisone to methylprednisolone.
A patient takes 40 mg of prednisone daily. Using E1 = 5 and E2 = 4, the equivalent methylprednisolone dose is D2 = 40 * (4 / 5) = 32 mg. The hydrocortisone-equivalent burden is 40 * (20 / 5) = 160 mg, which is a pharmacologic dose. Both drugs are intermediate-acting, so the dosing frequency usually stays the same, and salt retention drops slightly.
Example 2: Convert hydrocortisone to dexamethasone.
A patient receives 100 mg of hydrocortisone. Using E1 = 20 and E2 = 0.75, the equivalent dexamethasone dose is D2 = 100 * (0.75 / 20) = 3.75 mg. Dexamethasone has no mineralocorticoid activity, so the salt-retention index falls from 100 to 0, which lowers fluid retention. Because dexamethasone is long-acting while hydrocortisone is short-acting, it can be given far less often.
Frequently Asked Questions
How do you convert one steroid dose to another?
Divide the current dose by that drug’s equivalent dose to get the number of equivalent units, then multiply by the target drug’s equivalent dose. For chronic dosing, use the total amount taken over 24 hours rather than a single dose, because the drugs last different lengths of time. The result matches glucocorticoid strength only, so you still check duration, salt retention, and the reason for the original prescription.
Which steroids cause the least fluid retention?
Dexamethasone, betamethasone, and triamcinolone have essentially no mineralocorticoid activity, so they cause little sodium and water retention even at high glucocorticoid doses. Hydrocortisone and cortisone retain the most salt, and prednisone, prednisolone, and methylprednisolone sit in between. That is why a long-acting agent is often chosen when swelling, high blood pressure, or heart failure is a concern, and it is what the calculator’s salt-retention index highlights.
Does converting change how often I take the dose?
It can. Moving to a longer-acting steroid usually lets you give the same daily amount less often, while moving to a shorter-acting one often means splitting the daily amount into more doses. Equivalent-dose tables match total strength, not schedule, so the frequency is adjusted separately. Any change to a chronic or high-dose regimen should be confirmed with the prescriber or pharmacist, including whether a taper is needed.