Medical cannabis dosing by form comes down to two variables: how much THC or CBD each unit delivers and how fast the body absorbs it. Inhaled forms such as flower and vape cartridges act within minutes, so a patient can adjust in small steps during one session. Edibles, capsules, and drinks can take 30 to 120 minutes to peak, so the starting amount is smaller and the wait between adjustments is longer.
cannabis product dose calculator chart
The rule that holds across every form is start low, go slow: begin at 1 to 2.5 mg THC, hold that amount for several days, and increase only after you know how the previous dose felt.
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How does onset time change the dose you can safely take?
Onset speed sets how quickly you can correct a dose. Fast forms give feedback in minutes, which makes them easier to titrate but easier to overuse. Slow forms hide the full effect for an hour or more, so a second dose taken too soon can stack on the first.
cannabis product dose calculator chart
- Inhaled flower or vape: onset 2 to 10 minutes, peak 15 to 30 minutes, effects last 2 to 4 hours.
- Sublingual tincture or oil: onset 15 to 45 minutes, peak 1 to 2 hours, effects last 3 to 6 hours.
- Edibles, capsules, drinks: onset 30 to 120 minutes, peak 2 to 4 hours, effects last 4 to 8 hours or longer.
- Topicals and patches: little to no psychoactive effect; local relief builds over 15 to 60 minutes.
What is a typical starting dose by form?
Tinctures and oral oils
A 10 mg per mL oil delivers 0.5 mg THC per 0.05 mL drop, which is why droppers matter more than bottle size. Start with one 0.25 mL to 0.5 mL serving held under the tongue for 60 to 90 seconds, then wait a full two hours before repeating.
thc mg dosage chart for beginners
Edibles and gummies
Most US states cap a single serving at 10 mg THC and a package at 100 mg, and many patients find 2.5 mg is plenty for sleep or pain at first. Cut the gummy so the pieces are equal, and never take a second piece inside the first two hours.
Inhaled flower
One inhalation of flower typically delivers 1 to 3 mg THC, depending on potency and inhalation depth. Take one draw, wait 10 to 15 minutes, and add a second only if the first fell short.
Vape cartridges and concentrates
Metered-dose vape batteries release a fixed amount per puff, which makes them the easiest form to count. Concentrates run far stronger than flower, so a single small puff is a full starting dose.
Capsules, drinks, and topicals
Capsules behave like edibles but with a slower, flatter curve, often 60 to 120 minutes to onset. Drinks can hit faster than solid edibles because liquid absorbs sooner. Topicals are applied to the painful area and are not dosed for a head effect.
Why does convenience push patients toward vapes and gummies?
Convenience now decides form for many patients: a metered vape needs no grinder, no lighter, and no smoke, and a wrapped gummy needs no measuring. Single-serve packaging also removes the arithmetic that causes most dosing errors.
The tradeoff is that convenient forms are often the hardest to reverse. A vape puff fades in two hours, while an edible taken by mistake can last most of a day.
How should you titrate after the first dose?
- Log the form, milligrams, time, and effect for every dose.
- Hold the same dose for 3 to 7 days before changing it.
- Raise by no more than 1 to 2.5 mg THC per adjustment for oral forms.
- Separate oral doses by at least 4 hours, and inhaled doses by at least 2 hours.
- Ask a pharmacist or physician before combining cannabis with opioids, benzodiazepines, or blood thinners.
Frequently asked questions
Can you split a gummy for a smaller dose?
Yes, if it is a uniform gelatin or pectin gummy, though the halves may not be perfectly equal. A kitchen scale turns that guess into a number.
What should you do if a dose feels too strong?
Stay hydrated, sit or lie somewhere safe, and remember that no fatal overdose from cannabis has been recorded. Symptoms usually ease within a few hours, but seek medical help for chest pain, severe vomiting, or confusion.