Convert between benzodiazepine doses using diazepam equivalents. Full equivalence table for 12 benzodiazepines with half-life, onset, duration, and Ashton Manual taper guidance.
The Benzodiazepine Conversion Calculator converts between benzodiazepine doses using the standard diazepam-equivalent reference. Covering 12 commonly prescribed benzodiazepines, it provides equivalent dosing, half-life comparison, onset speed, duration of action, and taper guidance based on the Ashton Manual protocol.
Benzodiazepine cross-tapering and dose conversion is one of the most clinically important calculations in psychiatry and addiction medicine. Patients frequently need to switch between agents — for example, converting from short-acting alprazolam (Xanax) to long-acting diazepam (Valium) for a controlled taper — and accurate equivalent dosing is essential to prevent both under-dosing (causing withdrawal seizures) and over-dosing (causing sedation or respiratory depression).
This calculator uses standard equipotent dose ratios referenced in the Ashton Manual, British National Formulary, and major pharmacology textbooks. It also generates an estimated taper schedule using conservative 5-10% weekly reductions, the approach supported by the most evidence for minimizing withdrawal symptoms. Check the example with realistic values before reporting.
Accurate benzodiazepine dose conversion is critical for safe medication switches and tapering. This calculator provides clinicians and informed patients with instant equivalence calculations, reference tables, and evidence-based taper guidance. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain. Use this clarification to avoid ambiguous interpretation. Align this note with review checkpoints.
Diazepam Equivalent (mg) = (Total Daily Dose / Source Drug Equiv) × 5 Target Drug Dose (mg) = (Diazepam Equivalent / 5) × Target Drug Equiv Equivalent doses (mg ≈ 5 mg Diazepam): Alprazolam 0.5, Chlordiazepoxide 25, Clonazepam 0.5, Diazepam 5, Lorazepam 1, Oxazepam 15, Temazepam 15, Triazolam 0.25
Result: Total: 1.5 mg/day alprazolam = 15 mg/day diazepam = 7.5 mg BID.
Alprazolam 0.5 mg = 5 mg diazepam. Total daily dose 1.5 mg = 3 doses × (5/0.5) = 15 mg diazepam. Diazepam is split into 2 doses due to its long half-life, giving 7.5 mg twice daily.
Benzodiazepines all act on GABA-A receptors, but they differ in potency (receptor binding affinity), onset (lipophilicity and absorption), half-life (hepatic metabolism and active metabolites), and selectivity (anxiolytic vs. anticonvulsant vs. hypnotic effects). These differences explain why equivalent doses vary so much — 0.5 mg of alprazolam has the same clinical effect as 25 mg of chlordiazepoxide, a 50-fold dose difference.
Physical dependence can develop within 2-4 weeks of daily use and is nearly universal after months of use. The brain downregulates GABA-A receptors in response to chronic benzodiazepine exposure, resulting in tolerance (needing more for the same effect) and withdrawal when the drug is reduced. Approximately 40% of long-term users will experience significant withdrawal symptoms during tapering.
Some patients experience protracted withdrawal symptoms lasting months to years after complete cessation. These include anxiety, insomnia, tinnitus, depersonalization, paresthesias, and cognitive difficulties. While controversial, protracted withdrawal is increasingly recognized and may reflect slow receptor recovery. It is more common after long-term use of high-potency short-acting agents (alprazolam, lorazepam).
Diazepam has a long half-life (20-100 hours) with active metabolites lasting even longer. This provides stable blood levels without interdose withdrawal, making it the preferred agent for controlled tapering. Short-acting agents like alprazolam cause fluctuating blood levels that make tapering difficult.
The Ashton Manual recommends reducing by 5-10% of the current dose every 1-2 weeks. At higher doses (>20 mg diazepam equiv), 10% reductions are tolerable. Below 10 mg, slow to 5% or smaller absolute reductions (0.5-1 mg) every 2-4 weeks. Total taper duration is typically 6-18 months for long-term users.
Abrupt cessation or rapid dose reduction can cause life-threatening complications: grand mal seizures, delirium tremens-like syndrome, psychosis, and status epilepticus. Even gradual tapering can cause insomnia, anxiety, tremor, dysphoria, and perceptual disturbances. Medical supervision is essential.
No — equivalence ratios are approximate and based on clinical observation, not precise pharmacological equivalence. Individual variation in metabolism, receptor sensitivity, and tolerance means equivalent doses may differ by 20-50% between patients. These tables are starting points, and doses must be adjusted clinically.
The Ashton Manual, written by Professor C. Heather Ashton (Newcastle University), is the most widely referenced guide for benzodiazepine withdrawal and tapering. Published in 2002 and updated since, it provides detailed protocols for switching to diazepam and tapering at individualized rates.
Z-drugs act on the same GABA-A receptors but with different subunit selectivity. Approximate equivalents exist (zolpidem 10 mg ≈ diazepam 10 mg) but they are less reliable than benzodiazepine-to-benzodiazepine conversions. Z-drug tapering may require direct dose reduction rather than cross-tapering.