Melatonin Dose Calculator

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Walk-through

How to Use This Calculator

3 steps

1

Pick Your Use Case

Select what you're using melatonin for: sleep onset, eastward jet lag, westward jet lag, or shift work. Each use case has its own commonly cited dose range and timing — they are not interchangeable.

2

Choose an Age Band

Select Adult or Older Adult (65+). Older adults commonly start at the low end of the range shown, since melatonin clearance and sleep architecture change somewhat with age.

3

Read the Dose and Timing

The result card shows a commonly cited dose range in milligrams and when to take it. The Use Case tab shows all four scenarios side by side, and the Notes tab covers children, medication interactions, and regulatory status — read it before use.

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Reference

Formula & Methodology

1 formula

Use-Case Lookup Table

Guidance = lookup(useCase)

This is not an arithmetic formula — it is a lookup table of commonly cited, low-dose-first melatonin guidance keyed by use case. Sleep onset uses a 0.5-3mg range taken 30-60 minutes before bedtime; eastward jet lag uses a wider 0.5-5mg range taken near the destination bedtime for the first 2-4 nights (eastward travel is generally the harder direction to adjust to); westward jet lag uses a narrower 0.5-3mg range, often needed for only 1-2 nights or skipped entirely; shift work uses a 0.5-3mg range timed to the start of the daytime sleep period. These ranges reflect general sleep-medicine guidance, not a personalized prescription.

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High YMYL

Trust, Methodology & Sources

Reviewed by Calculover Editorial Review · Updated 2026-07-23 · 1 sources

Editorial accountability

Author: Quinn Sumner - Editor

Owner: Quinn Sumner - Editorial owner

Reviewer: Calculover Editorial Review - Sleep-medicine-source review

Last reviewed: 2026-07-23

Last verified: 2026-07-23

Data effective: 2026-07-23

Methodology

This calculator presents a lookup table of commonly cited, low-dose-first melatonin guidance by use case (sleep onset, eastward jet lag, westward jet lag, shift work), drawn from general sleep-medicine sources including NIH's National Center for Complementary and Integrative Health. It performs no personalized calculation from user health data — it surfaces the applicable published range and timing for the selected use case.

Assumption: The user is a generally healthy adult (or is using the Older Adult band to see guidance skewed toward the low end of the range) without conditions or medications that would change safe melatonin use.

Assumption: Dose ranges reflect commonly cited general guidance, not a clinical trial-derived optimal dose for any individual.

Assumption: Jet lag timing protocols assume travel across multiple time zones is the primary driver of sleep disruption, not an unrelated sleep disorder.

Limitations & guidance

This calculator does not provide pediatric dosing guidance — children should only take melatonin under a pediatrician's direction.

It does not check for interactions with medications such as blood thinners, immunosuppressants, diabetes medications, blood pressure medications, or sedatives.

Over-the-counter melatonin supplements in the US are not held to the same manufacturing standards as prescription drugs, so actual pill content can vary from the labeled dose.

This tool does not replace an assessment by a physician or pharmacist, particularly for anyone with an existing health condition or taking other medications.

Professional guidance: Melatonin Dose Calculator is for general educational purposes only. It is not a prescription and does not replace individualized advice from a healthcare provider, especially for children, pregnancy, other medications, or underlying health conditions.

Primary sources

Melatonin: What You Need To Know - National Center for Complementary and Integrative Health (NCCIH), National Institutes of Health

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Glossary

Key Terms Explained

5 terms

Melatonin A hormone naturally produced by the pineal gland in response to darkness, which helps regulate the sleep-wake cycle. Supplemental melatonin is sold over the counter in the US and used to nudge the body's internal clock or make falling asleep easier.

Sleep Onset The transition from wakefulness into sleep. Melatonin taken shortly before a target bedtime is commonly used to shorten the time it takes to fall asleep, particularly for people with a delayed body clock.

Jet Lag Protocol A schedule of melatonin timing (and often light exposure) designed to help the body's internal clock adjust to a new time zone faster. Protocols differ by travel direction because eastward and westward shifts affect the circadian rhythm differently.

Circadian Rhythm The roughly 24-hour internal body clock that governs sleep-wake timing, hormone release (including melatonin), and other physiological cycles. Travel across time zones and shift work both disrupt this rhythm.

Low-Dose-First Approach A strategy of starting at the lowest commonly cited effective dose and only increasing if needed, rather than starting at a high commercial dose. Research suggests lower melatonin doses are often just as effective as higher ones for sleep onset, with less next-day grogginess.

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Scenarios

Real-World Examples

3 worked examples

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Sam

Trouble falling asleep at a consistent bedtime

Use case Sleep onset Age band Adult

Sam's commonly cited range is 0.5-3mg, taken 30-60 minutes before the target bedtime. Starting at the low end (0.5-1mg) is a reasonable first try — many sleep-onset studies use doses at this low end rather than the 5-10mg often sold over the counter.

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Priya

Flying from New York to London (eastward, 5-hour shift)

Use case Jet lag — traveling east Age band Adult

Priya's commonly cited range is 0.5-5mg, taken close to London bedtime starting the day of or day after arrival, for the first 2-4 nights. Eastward travel is generally the harder direction to adjust to, so melatonin timed to the new bedtime can help pull her body clock forward faster.

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Marcus

Rotating onto night shifts, needs to sleep during the day

Use case Shift work (daytime sleep) Age band Adult

Marcus's commonly cited range is 0.5-3mg, taken right before his intended daytime sleep period in a dark, quiet room. Pairing the dose with blackout curtains and avoiding morning sunlight before bed matters roughly as much as the dose itself for daytime sleep quality.

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Deep Dive

Melatonin Dosing Depends Entirely on Why You're Taking It

3 chapters · 4 min read

Melatonin is one of the most widely used sleep supplements, but a single "right dose" doesn't exist — the amount and timing that make sense for falling asleep at a normal bedtime are different from what's commonly cited for jet lag or for sleeping during the day after a night shift. This calculator organizes commonly cited, low-dose-first guidance by use case so you can see the dose range and timing that applies to your specific situation, alongside the caveats that matter before you use it.

Why the Same Dose Doesn't Fit Every Use Case

Melatonin works by supplementing the same hormone your body releases naturally in response to darkness — but how you want to use that signal changes with the situation. For everyday sleep onset, a low dose taken 30-60 minutes before your usual bedtime nudges an already-roughly-normal body clock. For jet lag, you're trying to actively shift your body clock to match a new time zone, which is a different job, and eastward shifts (which move your bedtime earlier) are generally harder to adjust to than westward shifts (which move it later) — so the commonly cited dose ranges and night counts differ by direction. For shift work, the goal is neither shifting the whole clock nor a normal-hours bedtime, but signaling sleep during daylight hours when your body's natural melatonin release is suppressed by light.

The Case for Starting Low

A recurring theme across sleep-medicine guidance is that lower melatonin doses are often just as effective as higher ones, particularly for sleep onset — some research uses doses as low as 0.3mg, far below the 5-10mg commonly sold over the counter in the US. Higher doses are not necessarily more effective, and can increase the odds of next-day grogginess or vivid dreams. Starting at the low end of the commonly cited range shown here, and only increasing if it doesn't help, is a widely recommended approach across all four use cases.

What This Tool Doesn't Cover

This calculator surfaces general, publicly cited starting-dose guidance — it is not a personalized medical recommendation and doesn't account for your health history, other medications, or specific circumstances. It does not cover pediatric dosing at all; children should only take melatonin under a pediatrician's direction. It also doesn't account for interactions with common medications like blood thinners, immunosuppressants, diabetes medications, or sedatives. See the Notes tab for the full list of situations where you should check with a healthcare provider before use.

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Questions

Frequently Asked Questions

6 questions

What's a good starting dose of melatonin?+

Commonly cited guidance suggests starting low — for example, 0.5-1mg for sleep onset — and only increasing if that doesn't help. This applies across use cases: lower doses are often just as effective as higher ones, with less risk of next-day grogginess.

Is melatonin an over-the-counter supplement?+

Yes, in the United States melatonin is sold over the counter as a dietary supplement, which means it isn't regulated with the same manufacturing oversight as prescription drugs — actual pill content can vary from the labeled dose. In many other countries, including much of Europe, melatonin is only available by prescription.

Does jet lag direction matter for melatonin timing?+

Yes — eastward and westward travel use different timing protocols. Eastward travel shifts your bedtime earlier, which is generally the harder direction for your body clock to adjust to, so melatonin timed near the new bedtime for several nights is more commonly recommended. Westward travel shifts your bedtime later, which most people adjust to more easily, so melatonin is often used for fewer nights or skipped.

What units does this calculator use?+

Milligrams (mg), the standard unit for melatonin supplement dosing. The ranges shown reflect commonly cited low-dose-first guidance for each use case, not a single fixed number.

Is this a prescription or personalized dosing recommendation?+

No — this tool provides general educational guidance only, based on commonly cited public sources. It is not a prescription and does not replace a personalized recommendation from a healthcare provider.

Is this medical advice?+

No. This is informational only. Talk to a healthcare provider before giving melatonin to a child, before combining it with other medications, or if you have an underlying health condition.

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Your use case

Suggested dose & timing

All four use cases, side by side

Important notes

How to Use This Calculator

Pick Your Use Case

Choose an Age Band

Read the Dose and Timing

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Sam

Priya

Marcus

Melatonin Dosing Depends Entirely on Why You're Taking It

Why the Same Dose Doesn't Fit Every Use Case

The Case for Starting Low

What This Tool Doesn't Cover

Frequently Asked Questions

Get a branded PDF of your results

Melatonin Dose Calculator

Your use case

Suggested dose & timing

All four use cases, side by side

Important notes

Related Calculators

How to Use This Calculator

Pick Your Use Case

Choose an Age Band

Read the Dose and Timing

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Melatonin Dosing Depends Entirely on Why You're Taking It

Why the Same Dose Doesn't Fit Every Use Case

The Case for Starting Low

What This Tool Doesn't Cover

Frequently Asked Questions

Get a branded PDF of your results

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