Melatonin Dosage Calculator

Melatonin is a hormone your brain releases in the evening as it gets dark. In the US, melatonin pills and gummies are sold as dietary supplements, so there is no FDA approved dose¹. This calculator does not invent one. It shows the amounts and timing that guidelines and trials describe for your goal, then works out how many pieces of your product match an amount in that range.

What the Melatonin Dosage Calculator Measures

It measures nothing about your body. It is a lookup of published evidence plus label math. It cannot know your health, your medicines or what is really in your bottle, and it gives no amount for children.

The Formula

Amount per piece (mg) = mg per serving / pieces per serving

Pieces = chosen amount (mg) / amount per piece (mg)

Liquid (mL) = chosen amount (mg) / (mg per serving / mL per serving)

The ranges behind the chosen amount come from American Academy of Sleep Medicine (AASM) practice parameters, Cochrane reviews and randomized trials² ³ ⁵.

How This Calculator Computes Your Result

First you choose who it is for. If you choose a child or teen, the tool shows guidance only, with no amount. For an adult, you pick a goal: falling asleep, jet lag after flying east or west, sleeping in the day after a night shift, or a diagnosed late body clock (delayed sleep-wake phase disorder). Jet lag also asks how many time zones you crossed, and you can add your bedtime.

For the product math, enter the form (tablet, capsule, gummy or liquid), the mg or mcg per serving from the label, and the pieces or mL per serving, then choose an amount up to the top of your goal's range. The tool rounds to whole pieces, or half pieces for scored tablets, and never goes past the top of the range. If one piece is already stronger than that, it says so instead of giving a count. Liquids are shown to 0.01 mL. A bedtime adds the clock times used in studies, and a short checklist flags when a doctor or pharmacist should check first.

What Your Result Means

More is not always better. In jet lag trials, doses above 5 mg worked no better, and 2 mg slow release melatonin worked poorly². For night shifts, higher doses did no better than lower ones⁵. For long-term trouble sleeping (chronic insomnia), the AASM suggests doctors not use melatonin⁸, and the American College of Physicians recommends cognitive behavioral therapy for insomnia first¹. In UK NHS guidance, the usual jet lag dose is one 3 mg tablet at bedtime after arrival⁴.

Melatonin Dosage by Weight for Children

There is no weight-based melatonin dose for children, and this calculator will not make one. Melatonin is not FDA approved for children's sleep, and the American Academy of Pediatrics (AAP) says there are no specific guidelines on melatonin dosing for children¹¹. The AASM advises parents to talk with a pediatric clinician first, notes that many sleep problems are better managed with changes in schedules, habits or behaviors, and leaves the dose and timing to that clinician¹⁰. The AAP adds that melatonin should be used only after a talk with the pediatrician¹¹.

Weight has not proved a useful guide. In a trial of 72 children aged 6 to 12, three weight-based amounts worked about the same, so the higher amounts added nothing¹⁴. In a Swedish study of 1,554 prescriptions, children were prescribed similar maximum doses whatever their weight or age¹⁵. And because product content varies, an exact number on paper is not an exact number in the gummy¹³.

Accidental swallowing is a real risk. Reports to US poison centers of children swallowing melatonin rose 530 percent from 2012 to 2021, reaching 52,563 in 2021, and two children died¹². Keep melatonin out of reach like any medicine¹⁰. If a child swallows some, call Poison Help at 1-800-222-1222, open 24 hours in the US¹⁸.

Why the Label Amount May Not Match

In a 2023 test of 25 US melatonin gummy brands, 22 were mislabeled. Real melatonin ranged from 74 to 347 percent of the label, and one product had none but contained CBD¹³. Other testing has found from under half to more than four times the labeled amount, and the AASM suggests choosing a product with the USP Verified Mark¹⁰. For gummies, your result shows what the 2023 range would mean for your amount.

Who Should Check With a Doctor First

Little is known about melatonin's safety in pregnancy or breastfeeding¹. People with epilepsy or who take blood thinners need medical supervision¹. Many medicines can change its sleepy effect, including fluvoxamine, benzodiazepines, blood pressure medicines, warfarin, carbamazepine and other sleep medicines¹⁶. The NHS also asks people with liver or kidney problems or an autoimmune condition to tell a doctor or pharmacist first¹⁷. Melatonin may stay active longer in older adults and cause daytime drowsiness¹.