The standard advice for edibles goes like this: take 5 to 10mg, wait two hours, see how you feel. It’s not wrong, but it’s not enough. A 130-pound first-timer eating a gummy on an empty stomach will hit very differently from a 220-pound regular consumer eating one after dinner. The same 10mg behaves like two different doses in two different bodies. That gap is what an edible timing calculator is built to fill.
I’m Erick, and I built GummyClock as a free harm-reduction tool for exactly this problem. Here’s what a good timing calculator actually does, what it needs from you to do it well, and how to read the results so they help you plan your evening instead of adding noise to it.
When you eat a THC edible, the active compound takes a long route to your bloodstream. It passes through your stomach, gets absorbed in the small intestine, and goes straight to your liver before reaching the rest of your body. The liver converts a chunk of the original THC into 11-hydroxy-THC, a metabolite that crosses into the brain more readily and feels stronger than the parent compound. This is the reason edibles hit harder per milligram than smoking the same amount.
A timing calculator models this whole journey. The math behind it is called a two-compartment pharmacokinetic model, which sounds intimidating but really just describes two things: how fast THC enters your blood, and how fast it leaves. The peak you feel happens when those two rates briefly balance. After that, the curve falls as your body clears the drug.
The calculator’s job is to predict where, on your specific curve, the peak lands and how long the comedown takes. Generic edible advice can’t do that, because it doesn’t know anything about you.
A useful calculator needs four things from you, and each one does real work.
Weight is the biggest single variable. The same dose distributes through more tissue in a larger body, which lowers peak intensity. A 200-pound person and a 120-pound person eating identical 10mg gummies experience meaningfully different curves.
Height and age combine with weight to estimate body composition. Body fat matters because THC is highly fat-soluble. Fatty tissue acts as a slow-release reservoir, pulling THC out of your blood and trickling it back over hours. Higher body fat means a slightly lower peak but a longer tail. The Deurenberg formula estimates body fat percentage from height, weight, and age, and a good calculator adjusts the curve accordingly.
Dose is the obvious one, but worth a note: a 10mg gummy from a regulated dispensary is usually within a few percent of its label. A 10mg gummy from an unregulated source could be anywhere from 5mg to 25mg. If you don’t trust the label, treat the calculator output as a best-case scenario and start lower.
The calculator does not need your name, email, or location. The whole calculation runs in your browser. Nothing about your body or your dose gets stored anywhere.
A good output shows you three moments, not just one. The onset is when you’ll start to feel something, usually 45 to 90 minutes after eating. The peak is when the effects are strongest, typically two to three hours in. The comedown is the long descent back to baseline, another four to six hours after the peak for most people.
If you ate a 10mg gummy at 6 PM, a calculator should be able to tell you: you’ll start feeling it around 7 PM, peak around 8:30 PM, and be functional again by 11 PM. That’s specific enough to plan an evening around. “Edibles last 4 to 8 hours” is not.
The most useful number on the curve is your peak time. Plan to be somewhere comfortable when it hits. Don’t have a difficult phone call scheduled, don’t be driving, don’t be locked into anything that requires sharp attention. The peak window is short. Forty-five minutes after the high point you’ll already be on the way down.
Tolerance matters and is hard to model from inputs alone. A regular consumer who eats edibles three times a week will feel a 10mg dose much less than someone whose last edible was a year ago. If you have meaningful tolerance, expect a less intense peak than the calculator shows. If you have none, treat the predicted peak as the upper bound, not the average.
Stomach contents also matter. An edible on an empty stomach often hits sooner and harder. The same edible after a heavy meal may take an extra hour to come on and feel softer at peak. I’m partial to taking edibles about an hour after a normal meal, which gives a predictable middle-ground curve.
No model handles strain chemistry, terpene profile, or the difference between a 10mg distillate gummy and a 10mg full-spectrum live-resin gummy either. Those variables are real, but their effects are smaller than dose, body composition, and stomach state.
The point of a timing calculator isn’t to replace your judgment. It’s to give you a calibrated starting point so you can plan with intent instead of guessing. Run your numbers, look at the curve, decide if the timing fits your evening, and adjust the dose down if it doesn’t.
Open the GummyClock calculator and run your own numbers. It takes about thirty seconds, costs nothing, and shows you the actual shape of what you’re about to feel.
Get a personalized timing prediction for your next edible.
Open the GummyClock calculator