A benzodiazepine conversion calculator converts a dose of one benzodiazepine into an equivalent dose of another benzodiazepine, using diazepam or lorazepam as the reference drug. The tool applies published equivalence ratios rather than measuring drug effect directly. This page covers six areas: the math behind the conversion, standard equivalent doses across common benzodiazepines, the effect of route of administration and bioavailability on a conversion, the reason published ratios differ between clinical sources, the factors that change a conversion's real-world accuracy, and the safety limits of using a calculated dose.
How Does a Benzodiazepine Conversion Calculator Work?
A benzodiazepine conversion calculator works in two steps: it converts a source drug's dose into a common reference dose, then converts that reference dose into an equivalent dose of the target drug. This two-step process exists because a direct ratio between every possible drug pair does not exist in published literature; only ratios against one reference drug exist. The calculator uses the reference dose as a bridge between any two benzodiazepines, regardless of which pair a user selects.
What Reference Dose Does a Benzodiazepine Conversion Calculator Use?
Most benzodiazepine conversion calculators anchor every conversion to a fixed dose of diazepam, commonly 10mg, and a smaller number of tools anchor to 1mg of lorazepam instead. A shared reference point removes the need for a separate ratio between every possible drug pair; one ratio per drug against the reference is enough to calculate any conversion. Two standards exist across published sources: a diazepam-based standard, used by the Ashton Manual, and a lorazepam-based standard, used by some clinical tools such as ClinCalc and MDCalc. Both standards produce correct results within their own system, which explains why two calculators can show different numbers while both remain accurate.
This table compares the two reference systems used across published benzodiazepine equivalence sources.
Standard | Reference Dose | Sources Using This Standard |
Diazepam-based | 10mg diazepam | Ashton Manual, most published equivalence charts |
Lorazepam-based | 1mg lorazepam | Selected clinical calculators, including ClinCalc and MDCalc |
What Information Do You Need to Enter Into a Benzodiazepine Conversion Calculator?
A benzodiazepine conversion calculator needs four inputs: the current drug, the current dose per intake, the number of intakes per day, and the target drug. Frequency matters because the calculator works from total daily dose, not from a single intake amount. Some calculators also include an optional conservative reduction setting, for example calculating 50 to 75 percent of the full equivalent dose instead of 100 percent, for cases where a lower starting point is wanted. The checklist below lists what to prepare before using the tool.
1. Identify the current benzodiazepine by name.
2. Record the dose taken at each intake.
3. Count the number of intakes per day.
4. Select the target benzodiazepine.
5. Choose a reduction setting, if the calculator offers one.
What Formula Turns One Benzodiazepine Dose Into Another?
The formula divides the current drug's total daily dose by its equivalent-to-reference ratio to produce a reference dose, then multiplies that reference dose by the target drug's ratio to produce the converted dose. A worked example demonstrates the arithmetic: a total daily dose of 1mg alprazolam, divided by a published ratio of 0.5mg alprazolam per 10mg diazepam reference unit, produces 2 reference units, equal to 20mg of diazepam on the reference scale. This example demonstrates the calculation only. A prescriber or pharmacist reviews any real dose change before it is acted on.
What Are the Standard Equivalent Doses for Common Benzodiazepines?
The values below are approximate ranges drawn from published clinical sources, including the Ashton Manual and other clinical pharmacy references, rather than one universal number. Different reputable sources do not always match exactly, and for some drug pairs the published range varies widely.
This table lists the diazepam-equivalent dose, half-life range, onset speed, and duration category for common benzodiazepines.
Drug | Diazepam-Equivalent Dose | Half-Life Range | Onset Speed | Duration Category |
Diazepam | 10mg (reference) | 20 to 100 hours (active metabolites extend this range) | Fast | Long-acting |
Alprazolam | 0.5mg (range 0.5 to 1mg) | 6 to 12 hours | Intermediate | Short to intermediate-acting |
Lorazepam | 1mg | 10 to 20 hours | Intermediate | Intermediate-acting |
Clonazepam | 0.25 to 0.5mg | 18 to 50 hours | Intermediate | Long-acting |
Chlordiazepoxide | 25mg | 5 to 30 hours (active metabolites extend this range) | Slow | Long-acting |
Temazepam | 20mg | 8 to 20 hours | Intermediate | Intermediate-acting |
Oxazepam | 20mg | 4 to 15 hours | Slow | Short-acting |
Triazolam | 0.5mg | 1.5 to 5.5 hours | Fast | Short-acting |
Flurazepam | 15 to 30mg | 40 to 250 hours (active metabolite) | Fast | Long-acting |
Estazolam | 1 to 2mg | 10 to 24 hours | Fast | Intermediate-acting |
Quazepam | 20mg | 25 to 100 hours (active metabolites) | Fast | Long-acting |
Clorazepate | 15mg | 30 to 100 hours (active metabolite) | Fast | Long-acting |
Midazolam (oral) | 7.5 to 10mg | 1.5 to 2.5 hours | Fast | Short-acting |
What Dose of Diazepam Is Equivalent to Alprazolam (Xanax)?
Roughly 0.5mg of alprazolam equals 10mg of diazepam, with published ranges of about 0.5 to 1mg depending on source. Alprazolam has a shorter half-life than diazepam, and its conversion ratio is one of the more debated figures across published sources, which is why users often see slightly different numbers between tools. The Ashton Manual and clinical calculators such as ClinCalc both publish figures within this range.
What Dose of Diazepam Is Equivalent to Lorazepam (Ativan)?
Roughly 1mg of lorazepam equals 10mg of diazepam, based on standard published charts. Lorazepam has no active metabolites and near-complete oral bioavailability, which is why it is often the preferred substitute in patients with liver impairment, a point connected to the accuracy factors covered later on this page.
What Dose of Diazepam Is Equivalent to Clonazepam (Klonopin)?
Roughly 0.25 to 0.5mg of clonazepam equals 10mg of diazepam, depending on source. Clonazepam has a long half-life, and it is sometimes used directly for tapering without switching to diazepam first, unlike shorter-acting drugs.
What Dose of Diazepam Is Equivalent to Chlordiazepoxide (Librium)?
Roughly 25mg of chlordiazepoxide equals 10mg of diazepam. Chlordiazepoxide has a long history of use in alcohol withdrawal protocols, and most published equivalence literature for this drug class originates from that setting rather than from general anxiety treatment.
What Dose of Diazepam Is Equivalent to Temazepam, Oxazepam, Triazolam and Other Common Benzodiazepines?
The drugs below are grouped together because individual search volume for each is lower than for the drugs already covered above. Each equivalent dose is expressed against the same 10mg diazepam reference.
• Temazepam: 20mg equals 10mg diazepam.
• Oxazepam: 20mg equals 10mg diazepam.
• Triazolam: 0.5mg equals 10mg diazepam.
• Flurazepam: 15 to 30mg equals 10mg diazepam.
• Estazolam: 1 to 2mg equals 10mg diazepam.
• Quazepam: 20mg equals 10mg diazepam.
• Clorazepate: 15mg equals 10mg diazepam.
• Midazolam (oral): 7.5 to 10mg equals 10mg diazepam, with limited published data since midazolam is used mostly by injection.
What Is the Equivalent Dose for Less Common Benzodiazepines Like Bromazepam, Nitrazepam, Prazepam and Clobazam?
The drugs below appear in the full Ashton Manual equivalence table but are missing from most simplified calculators. Each entry includes a market aim classification, since this changes the reason a person may have been prescribed it.
This table lists diazepam-equivalent doses for less commonly searched benzodiazepines.
Drug | Diazepam-Equivalent Dose | Market Aim | Available in the United States |
Bromazepam | 5 to 6mg | Anxiolytic | Not marketed in the United States |
Nitrazepam | 10mg | Hypnotic | Not marketed in the United States |
Prazepam | 10mg | Anxiolytic | Discontinued in the United States |
Clobazam | 20mg | Anticonvulsant | Available under a different brand name |
Halazepam | 20mg | Anxiolytic | Discontinued in the United States |
Ketazolam | 15 to 30mg | Anxiolytic | Not marketed in the United States |
Loprazolam | 1 to 2mg | Hypnotic | Not marketed in the United States |
Lormetazepam | 1 to 2mg | Hypnotic | Not marketed in the United States |
Medazepam | 10mg | Anxiolytic | Not marketed in the United States |
Nordazepam | 10mg | Anxiolytic | Not marketed as a standalone product in the United States |
Flunitrazepam | 1mg | Hypnotic | Not marketed in the United States |
What Is the Equivalent Dose for Z-Drugs (Zolpidem, Zopiclone, Eszopiclone, Zaleplon) Compared to Diazepam?
Zolpidem, zopiclone, eszopiclone, and zaleplon are not chemically benzodiazepines, but they act on the same receptor system and appear in the Ashton Manual's equivalence table with their own diazepam-equivalent doses. Zolpidem at 20mg equals 10mg diazepam. Zopiclone at 15mg equals 10mg diazepam. Eszopiclone at approximately 3mg equals 10mg diazepam. Zaleplon at 20mg equals 10mg diazepam. These drugs are intended for short-term use only, matching published source guidance. The broader difference in withdrawal pattern between Z-drugs and benzodiazepines is covered in the linked supplementary section further down this page.
How Do Route of Administration and Bioavailability Affect Benzodiazepine Conversion?
Published benzodiazepine equivalence data is based on oral dosing, and switching to an intravenous or intramuscular form changes the real effective dose because of bioavailability differences between routes. This distinction affects two areas covered below: the studied IV midazolam to IV lorazepam ratio, and the general effect of oral bioavailability on any converted dose.
Why Is the IV Midazolam to IV Lorazepam Conversion Different From Oral Benzodiazepine Conversions?
The IV midazolam to IV lorazepam ratio has been studied in a controlled clinical trial in mechanically ventilated patients, unlike most benzodiazepine conversions, which rest on expert opinion rather than trial data. The commonly cited ratio is roughly 1mg IV lorazepam to 2mg IV midazolam. This figure applies to chronic continuous infusion, not single oral doses, and it is not applied to oral conversions. ClinCalc references the source trial behind this figure.
How Does Oral Bioavailability Change the Real Effective Dose of a Benzodiazepine?
Oral bioavailability is the percentage of an oral dose that actually reaches the bloodstream. Most benzodiazepines used in this calculator, including lorazepam and diazepam, have over 90 percent oral bioavailability, while oral midazolam is much lower, around 35 to 75 percent, due to a significant first-pass effect in the liver. A straight milligram-for-milligram equivalence assumes similar absorption between drugs, so drugs with lower or more variable bioavailability need extra caution when converted. ClinCalc publishes the bioavailability figures used on this page.
Why Do Benzodiazepine Conversion Ratios Differ Between the Ashton Manual and Other Clinical Sources?
Benzodiazepine equivalency data comes from clinical experience, uncited tables, and small studies rather than large controlled trials, which is the main reason published ratios differ between sources. Much of the published literature originates from alcohol withdrawal treatment settings rather than from general anxiety or insomnia treatment. Unlike opioids, regulators do not require drug manufacturers to publish an official equipotent dose for benzodiazepines, which is part of why no single authoritative number exists. Small differences between reputable sources are normal, and for some drug pairs the accepted range varies by a factor of ten or more. No single named source is more correct than another across every drug pair.
This table shows how the same drug pairs are converted differently across three commonly cited sources.
Drug Pair | Ashton Manual | ClinCalc | MDCalc |
Alprazolam to Diazepam | 0.5mg to 10mg | 0.5mg to 10mg | 1mg to 10mg |
Lorazepam to Diazepam | 1mg to 10mg | 1mg to 10mg | 1mg to 10mg |
Clonazepam to Diazepam | 0.5mg to 10mg | 0.25mg to 10mg | 0.5mg to 10mg |
What Factors Change How Accurate a Benzodiazepine Dose Conversion Is?
A calculated conversion number is a starting estimate, not a fixed answer, and several patient-specific factors shift how it plays out in practice. Three factor categories affect accuracy: half-life differences between drugs, individual patient factors such as age and organ function, and reduced reliability at higher doses.
How Does Half-Life Affect a Benzodiazepine Conversion?
Two drugs can share the same equivalent dose on paper but feel very different in practice because of how fast each one is eliminated from the body. A short half-life drug, such as alprazolam or triazolam, clears faster than a long half-life drug, such as diazepam or clonazepam, and this difference affects dosing frequency and withdrawal timing, not just the raw converted number.
How Do Age, Liver Function, Kidney Function and Drug Interactions Change a Calculated Equivalent Dose?
Four patient factors change how a calculated dose behaves in practice. Elderly patients often need a fraction of the calculated dose due to increased sensitivity to benzodiazepines. Patients with liver impairment respond better to drugs without active metabolites, including lorazepam, oxazepam, and temazepam, and often need dose reductions of around 50 percent in mild to moderate impairment. Kidney function also changes how a dose behaves in the body. Concurrent medications can change absorption or clearance of a benzodiazepine. These factors are reasons a calculated number needs clinical review, not reasons to avoid the calculator.
Factor | Affected Group | Practical Adjustment Commonly Used |
Age | Elderly patients | Dose reduced to a fraction of the calculated amount |
Liver function | Patients with hepatic impairment | Preference for lorazepam, oxazepam, or temazepam; dose reduced by around 50 percent in mild to moderate impairment |
Kidney function | Patients with renal impairment | Dose reviewed by a prescriber before any change |
Drug interactions | Patients on multiple medications | Absorption and clearance reviewed against each interacting drug |
Why Does Benzodiazepine Conversion Become Less Reliable at Higher Doses?
Equivalency ratios are established at moderate, common therapeutic doses, and the relationship is not perfectly linear at higher doses, particularly for alprazolam. Doubling a dose does not always mean the equivalent target dose simply doubles as well.
What Are the Safety Risks of Using a Benzodiazepine Conversion Calculator Without Medical Guidance?
A calculated dose is meant to be reviewed by a prescriber or pharmacist before it is acted on. Three specific risk areas apply: using the tool to set a starting dose for someone new to benzodiazepines, withdrawal risk from a miscalculated conversion, and the separate risk profile of barbiturates that sometimes appear on the same charts.
Why Should a Benzodiazepine Conversion Never Set the Starting Dose for a Benzo-Naive Patient?
Equivalency calculators are built to convert between two doses a person already tolerates, not to determine a first-time dose for someone who has never taken a benzodiazepine. This is a defined limitation of the tool itself, and established clinical calculators such as MDCalc state this same restriction directly in their instructions.
What Withdrawal Risks Come From a Miscalculated Benzodiazepine Conversion?
An underestimated converted dose can trigger withdrawal symptoms, and in more serious cases, seizures, especially with abrupt changes. Physical dependence combined with a sudden change in drug exposure is the mechanism behind this risk. Supervised tapering, guided by a prescriber, addresses this risk directly.
Why Are Barbiturates Like Phenobarbital Sometimes Included in Benzodiazepine Conversion Charts?
Phenobarbital and secobarbital are not benzodiazepines, but they are commonly grouped in the same conversion charts because they are also used in alcohol withdrawal management and share a related, though not identical, mechanism. Barbiturates carry a higher risk of respiratory depression than benzodiazepines, so a figure for a barbiturate on a chart is not interchangeable in risk level with a true benzodiazepine equivalent. ClinCalc draws this distinction in its published material.
How Does a Benzodiazepine Conversion Fit Into a Larger Medication Switch or Taper Plan?
A single conversion calculation usually serves a bigger purpose: planning a taper, switching benzodiazepines for side effect reasons, screening for broader substance use, understanding the pharmacology behind the drug class, or preparing for a doctor visit. Each related situation connects to a dedicated page covered below.
How Does a Benzodiazepine Taper Calculator Use Conversion Values to Build a Withdrawal Schedule?
A conversion is usually the first step of a taper, not the whole plan; a dedicated Benzodiazepine to Diazepam Taper Calculator takes the converted diazepam-equivalent dose and reduces it gradually, commonly by 5 to 10 percent per week for long-term users, or faster for short-term use, rather than in one jump. The conversion step feeds into the taper, and the full taper method is covered on that linked page.
How Does the Ashton Manual Guide a Benzodiazepine Crossover to Diazepam?
The most cited clinical guide for switching short-acting benzodiazepines to diazepam before a taper is the Ashton Manual Benzodiazepine Withdrawal Guide, and its equivalency table is one of the main sources behind the numbers on this page. The conversion calculator supports planning a crossover using this method; the full withdrawal schedule is covered on that linked page.
How Does an Opioid Morphine Milligram Equivalent (MME) or Opiate Conversion Calculator Compare to a Benzodiazepine Conversion Calculator?
Different drugs in the opioid class convert to one common reference unit, morphine, through an Opioid to Morphine Milligram Equivalent Calculator, the same way this page converts benzodiazepines to a diazepam reference. Both tools are used by prescribers to compare total daily exposure or to switch between routes and drugs within the same class. Combined benzodiazepine and opioid use carries added risk, which is why some clinicians track both figures together. The CDC publishes the MME conversion factors used on the opioid side.
What Questions Should You Ask Your Doctor Before Switching Benzodiazepines?
Preparation for the conversation that follows a calculator result is covered on the Talking to Your Doctor About Medication Changes page. Bring these questions to an appointment:
• Does the converted number need adjusting for my age, liver function, or kidney function?
• How will the switch be staged over time?
• What withdrawal symptoms should I watch for?
• How soon should I follow up after the switch?
How Does Benzodiazepine Withdrawal Differ From Z-Drug (Zolpidem, Zopiclone) Withdrawal?
The deeper comparison between these two withdrawal patterns is covered on the Benzodiazepine and Z-Drug Withdrawal Symptoms page. Z-drugs act on a similar receptor system and can produce a related withdrawal pattern, and while this page's equivalence table gives their diazepam-equivalent dose, the timing and character of Z-drug withdrawal can differ from a true benzodiazepine's.
How Do Clinicians Use Other Equivalent Dose Calculators Like Opioid or Corticosteroid Converters?
The wider family of equianalgesic and equivalent-dose tools clinicians use day to day is listed on the Medical Dose Conversion Calculators Hub page. Opioid conversion solves the problem of comparing total daily opioid exposure across different drugs. Corticosteroid conversion solves the problem of comparing anti-inflammatory potency across different steroid drugs.
How Do Benzodiazepines Work in the Brain (GABA Receptor Mechanism)?
The full pharmacology behind this question is covered on the How Benzodiazepines Work in the Brain page. In short, benzodiazepines bind to the same GABA receptor sites in the brain, which is why doses can be compared using one reference drug in the first place. This shared binding site is the pharmacological basis for every equivalence figure on this page.
What Is the DAST-10 Screening Tool for Illicit Drug Use?
A separate tool clinicians sometimes use alongside a dose conversion calculator is the DAST-10 Drug Use Screening Tool. Clinicians assessing benzodiazepine use sometimes also use DAST-10 to check for broader illicit drug use patterns over the past year. This is a different kind of tool from a dose conversion calculator, built to screen for use patterns rather than to calculate a dose.