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Steroid Conversion Calculator

Corticosteroids vary widely in potency and duration of action, making direct dose-for-dose substitution unsafe. This calculator converts between eight common corticosteroids—hydrocortisone, cortisone, prednisone, prednisolone, triamcinolone, methylprednisolone, dexamethasone, and betamethasone—using standardised equivalency ratios. Clinicians use it to maintain therapeutic effect when switching medications or adjusting administration schedules. Always verify results with current clinical guidelines and patient-specific factors before implementation.

Last updated: May 14, 2026

Creators Łucja Zaborowska, MD, PhD

Reviewers Małgorzata Koperska and Adena Benn

413 people find this calculator helpful

Understanding Corticosteroid Potency

Corticosteroids are hormonal medications with potent anti-inflammatory, immunosuppressive, and anti-allergic properties. However, individual agents differ dramatically in strength—some require 20 mg doses while others work at 0.75 mg. Potency describes the relative anti-inflammatory effect compared to a reference standard, typically hydrocortisone.

Each corticosteroid also has a distinct duration of action, ranging from 8–12 hours for short-acting agents like hydrocortisone to 36–54 hours for long-acting drugs like dexamethasone. When converting between medications, clinicians must account for both potency and half-life to avoid under- or over-dosing.

Conversion is straightforward: express the current dose in hydrocortisone-equivalent units, then divide by the potency of the target drug. The resulting dose maintains comparable anti-inflammatory effect, though administration frequency may need adjustment based on duration of action.

Corticosteroid Equivalency Conversion

To convert from one corticosteroid to another, first normalise the current dose to hydrocortisone units, then apply the target drug's potency ratio. The formula for any conversion is:

Equivalent Hydrocortisone Dose = Current Dose × Current Drug Potency

New Steroid Dose = Equivalent Hydrocortisone Dose ÷ New Drug Potency

Hydrocortisone potency reference — Set at 1.0; all other steroids are expressed as multiples or fractions
Cortisone — Potency 0.8 (cortisone = hydrocortisone × 1.25)
Prednisone & Prednisolone — Potency 4.0 (each = hydrocortisone × 0.25)
Triamcinolone & Methylprednisolone — Potency 5.0 (each = hydrocortisone × 0.2)
Dexamethasone — Potency 30 (dexamethasone = hydrocortisone × 0.0375)
Betamethasone — Potency 30 (betamethasone = hydrocortisone × 0.03)

Example: Prednisone to Methylprednisolone Conversion

Consider a patient on 20 mg prednisone daily. To switch to methylprednisolone (Solu-Medrol) while maintaining equivalent anti-inflammatory effect:

Step 1: Convert prednisone to hydrocortisone equivalent: 20 mg prednisone × 4 = 80 mg hydrocortisone-equivalent

Step 2: Convert to methylprednisolone: 80 mg ÷ 5 = 16 mg methylprednisolone

The patient should receive 16 mg of methylprednisolone to achieve the same therapeutic effect. However, since methylprednisolone lasts 12–36 hours versus prednisone's 12–36 hours, the administration schedule may remain unchanged. For longer-acting agents like dexamethasone (36–54 hours), dosing frequency should decrease accordingly.

Duration of Action and Dosing Intervals

Corticosteroids fall into three categories by half-life: short-acting (hydrocortisone, cortisone: 8–12 hours), intermediate (prednisone, prednisolone, triamcinolone, methylprednisolone: 12–36 hours), and long-acting (dexamethasone, betamethasone: 36–54 hours).

When converting between agents, adjust the dosing frequency to match the new drug's duration. A patient on hydrocortisone 20 mg three times daily (60 mg/day total, short-acting) might convert to prednisone 15 mg once daily (intermediate-acting), not three divided doses. Similarly, 100 mg cortisone (short-acting) equals only 3 mg dexamethasone (long-acting), which may last multiple days.

Failure to adjust dosing intervals can result in subtherapeutic troughs or toxic peaks. Always consult the prescribing information and institutional guidelines for the specific agent.

Practical Considerations for Steroid Conversion

These key points help prevent dosing errors and adverse outcomes during corticosteroid switches.

Verify potency ratios from current guidelines — Anti-inflammatory potency can vary slightly between sources. Cross-reference this calculator's values with current clinical guidelines or your institution's formulary before finalising a prescription. Potency ratios are standardised by most national regulators but may be updated.
Account for bioavailability differences — These conversions assume equivalent oral or IV absorption. Intramuscular, topical, or inhaled corticosteroids have different bioavailability and should not be converted using this method. Always check whether the patient's current and proposed routes of administration are the same.
Adjust dosing frequency based on half-life — Converting from a short-acting to a long-acting steroid without reducing frequency risks accumulation and toxicity. Moving from long-acting to short-acting without increasing frequency may result in therapeutic failure. Consult pharmacokinetic data for the specific agent.
Monitor clinical response after conversion — Equivalent potency does not guarantee identical clinical effect in every patient. Individual factors—comorbidities, drug interactions, weight, renal/hepatic function—influence efficacy. Plan follow-up assessments within days to 1–2 weeks of switching to confirm therapeutic adequacy.

Frequently Asked Questions

What is the difference between hydrocortisone and dexamethasone?

Hydrocortisone is a short-acting glucocorticoid with potency 1.0 (the reference standard) and a half-life of 8–12 hours. Dexamethasone is a long-acting synthetic glucocorticoid with potency 30 and a half-life of 36–54 hours. A 100 mg dose of hydrocortisone is equivalent to only 3 mg of dexamethasone. The extended duration means dexamethasone requires less frequent dosing, reducing pill burden but increasing risk of accumulation if dose adjustments are not made.

Why do steroid doses vary so much between different medications?

Steroid potency—the ability to reduce inflammation per unit mass—varies by a factor of 30 or more. Dexamethasone and betamethasone are 30 times more potent than hydrocortisone by weight, so much smaller doses are needed. This reflects differences in receptor binding affinity and intracellular processing. Higher potency does not mean 'stronger' in a clinical sense; it simply means less mass is required to achieve the same anti-inflammatory effect. Prescribers must account for these potency differences to avoid dangerous dosing errors.

Can I switch steroids without consulting a doctor?

No. Steroid conversions require clinical judgment because patient-specific factors—underlying condition severity, concurrent medications, renal and hepatic function, weight—influence the appropriate dose. Additionally, equivalent anti-inflammatory potency does not guarantee identical clinical outcomes for every individual. Self-adjustment risks serious harm, including inadequate disease control, adrenal suppression, or glucocorticoid toxicity. Always consult your healthcare provider before any steroid medication change.

What happens if I maintain the same dosing schedule after switching to a long-acting steroid?

Long-acting steroids like dexamethasone (36–54 hours) accumulate if dosed as frequently as short-acting agents. For example, if a patient takes a long-acting steroid once daily for three consecutive days without dose reduction, blood levels may rise to two to three times the intended amount, increasing the risk of hyperglycemia, hypertension, osteoporosis, and infection. Dosing intervals must be extended for long-acting agents and shortened for short-acting ones to prevent accumulation or subtherapeutic troughs.

Are these conversions valid for all routes of administration?

No. These potency ratios apply only to oral and intravenous corticosteroids. Intramuscular injections, topical creams, and inhaled formulations have different absorption rates and bioavailability, so they cannot be converted using these ratios. A 1 mg inhaled triamcinolone, for example, does not equal the systemic dose calculated here. Always confirm the route of administration and use route-specific conversion guidelines for anything other than oral or IV therapy.

How long after switching steroids should I expect to see a change in symptoms?

This depends on the condition and the steroid's duration of action. Short-acting steroids reach steady state within 1–2 days; intermediate-acting steroids within 3–5 days; long-acting steroids within 7–10 days. Many patients notice clinical change within 24–72 hours if the dose is adequate, though some conditions—such as severe inflammatory disorders—may take 1–2 weeks to show full improvement. Your doctor should arrange follow-up within days to 1–2 weeks to assess therapeutic response and adjust the dose if necessary.

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