Benzodiazepine equivalents calculator
Pick a benzodiazepine and enter a dose. The tool converts to diazepam equivalents using the values in the Ashton Manual and the FDA labels, then shows equivalent doses across the class with half-life and onset. It's a bench lookup for cross-tapers, inpatient conversions, and alcohol withdrawal decisions. It's not a taper prescription. Pair it with the taper planner and a licensed prescriber.
Equivalence lookup
Choose a drug and enter a dose to see equivalents.
Reference data current as of June 8, 2026. Sources: Ashton Manual (Prof. C. Heather Ashton, Newcastle University); FDA prescribing information; ASAM 2020 Alcohol Withdrawal Management Guideline. See the clinician equivalents guide for the full source discussion.
How to read this
Benzodiazepine equivalents are useful starting points, not exact conversions. Different sources use different values, especially for alprazolam. When you cross-taper someone off a short-acting benzo, standard practice is to convert to a long-acting equivalent (usually diazepam or clonazepam), stabilize for a couple of weeks, then taper the long-acting drug slowly. The tool shows the ratios. The taper decision belongs with the licensed prescriber who knows the patient.
About this tool
Benzodiazepine equivalence tables are one of the most-used clinical references in psychiatry. They exist because benzodiazepines vary widely in potency: 0.25 mg of alprazolam is not the same as 0.25 mg of clonazepam or 0.25 mg of diazepam. When switching between agents, planning a taper, or converting a hospital admission dose to an outpatient regimen, having a shared unit matters.
The reference standard is the Ashton Manual (Prof. C. Heather Ashton, Newcastle University), first published in 2002 and continuously updated. Ashton is the definitive reference on benzodiazepine tapering and equivalence. FDA prescribing information for each drug provides the pharmacokinetic data (half-life and onset). This tool combines both to show, for any user-entered benzodiazepine and dose, the diazepam-equivalent dose across the class along with half-life and onset properties.
The calculator covers the common benzodiazepines used in psychiatric practice: diazepam (Valium), clonazepam (Klonopin), lorazepam (Ativan), alprazolam (Xanax), temazepam (Restoril), oxazepam (Serax), chlordiazepoxide (Librium), triazolam (Halcion), midazolam (Versed), and clorazepate (Tranxene). Each entry links to the drug page for the full write-up.
Two clinical patterns show up repeatedly. First, short-acting benzodiazepines (alprazolam, lorazepam, oxazepam, triazolam) cause interdose withdrawal because their plasma levels dip between doses, which is why tapers usually convert to longer-acting agents (diazepam, clonazepam) before reducing dose. Second, the elderly and patients with hepatic impairment often need agents without active metabolites (lorazepam, oxazepam, temazepam) because desmethyldiazepam accumulation from diazepam can cause days-long sedation. The tool shows half-life for exactly this reason. For full protocol-level guidance on tapering, see the benzodiazepine equivalents clinician guide and the taper planner.
Common questions
- What is a diazepam equivalent?
A diazepam equivalent is the dose of a given benzodiazepine that produces roughly the same GABA-A receptor effect as 10 mg of diazepam. It is used to compare doses across the class, plan cross-tapers, and orient safe conversions when switching between short-acting and long-acting benzodiazepines. The Ashton Manual (Prof. C. Heather Ashton, Newcastle University) is the reference standard for benzodiazepine tapering and equivalence tables. FDA prescribing information for each drug provides the pharmacokinetic data.
- Why convert to diazepam before tapering a benzodiazepine?
Diazepam has a long half-life (20 to 100 hours for the active metabolite desmethyldiazepam) and produces stable plasma levels between doses. Short-acting benzodiazepines like alprazolam and lorazepam cause interdose withdrawal because levels dip between doses, and each dip triggers rebound anxiety, insomnia, or physical symptoms. Converting to diazepam smooths the plasma curve and makes tapering much easier to tolerate. The Ashton Manual is built on this principle.
- What is 1 mg of alprazolam equivalent to in diazepam?
Approximately 20 mg of diazepam. Alprazolam is considered roughly 20 times more potent than diazepam on a milligram basis. This means a patient on 4 mg of alprazolam per day is on roughly 80 mg of diazepam per day equivalent, which is a substantial dose. The high potency of alprazolam is one of the reasons it is often the hardest benzodiazepine to taper.
- What is 0.5 mg of clonazepam equivalent to in diazepam?
Approximately 10 mg of diazepam. Clonazepam is roughly 20 times more potent than diazepam and has a longer half-life (30 to 40 hours) than most other benzodiazepines except diazepam itself. This makes clonazepam a common substitute for diazepam in tapering when diazepam is not tolerated or available.
- What is 1 mg of lorazepam equivalent to in diazepam?
Approximately 10 mg of diazepam. Lorazepam is intermediate potency (10 times diazepam) with a shorter half-life (10 to 20 hours). It does not have active metabolites, which is why it is often preferred in patients with hepatic impairment. For tapering, lorazepam is usually switched to diazepam or clonazepam first because of the interdose withdrawal problem.
- Do these equivalents apply to acute alcohol withdrawal?
Not directly. Acute alcohol withdrawal management uses symptom-triggered dosing (CIWA-Ar protocols) rather than fixed equivalents. Diazepam or chlordiazepoxide are typically used as the primary agent. The equivalents are useful for planning outpatient conversions and tapers, not for inpatient withdrawal management. See psychiatric medication and alcohol for more context.