calculator answers stay on this device
a tiny fentanyl calculator

what might your habit add up to?

Tell it where you are, how much you use, and how strong it seems. You’ll get a rough range for how much fentanyl may be in the powder.

it’s a rough estimate, not a dose.nothing you type is saved or sent.
totally optional side project ↓

the dope census

A bag, point, bundle, or jab can mean different things in different cities. The Census collects local words and weights so this little calculator can get better. You can use the calculator without filling it out.

add your city’s words

The Census saves only what you choose to submit. Do not include names, dealers, phone numbers, addresses, or exact locations.

Optional: video, research, and sources

The calculator adapts the central idea from published Los Angeles research. It is a simpler comparison tool, not a lab test or a measurement of what your body absorbs.

Read the research Read the New York Times story
step 1 · your region

Where are you, roughly?

Just the broad region — we don't ask your city or track anything. It only sets the average purity we start from, since that runs so different across the map.

step 2 · how you buy

How do you buy it?

Why this question matters: a "bag" in one city can mean something totally different somewhere else. Some places talk in points, niftys, grams, bundles, or stamp bags, and some do not call it dope at all.

step 3 · the quality

How good is it, hypothetically?

Compare it with the usual supply in the broad region you selected. The 7/10 marker is where this tool uses that region's starting assumption.

7/10
run-of-the-mill
7 · matches this region's average
1 · much weaker7 · starting assumption10 · much stronger
%

Estimated purity used in the calculation. The slider sets it from the regional baseline; edit it if you have a better aggregate assumption.

route still matters. how you use changes how much of it you absorb. dope math skips that choice here because those numbers are especially uncertain.
your reading

here’s the rough math

Illustrative random scenario — not a tested physical sample and not your information.
estimated fentanyl content · fixed logarithmic scale · not a danger score
—
estimated milligrams of fentanyl in the powder per day
what this estimate used
Purity source: rough regional averages from aggregate drug checking research in Los Angeles, BC, and Toronto. This is not a reading of any specific supply.
Go slow
Especially after any time off. Do a tester. Wait.
Not alone
Use with someone, or Never Use Alone: 800-484-3731.
Naloxone
Keep narcan close; make sure people know where it is.
Check it
You can't see strength. Get it checked if you can.

who made this

I built this tool because putting a scale on my own habit helped me talk more clearly about what I was experiencing. It made me feel infinitely better about being on 180 milligrams of methadone.

I figured if it helped me, it might help someone else.

contact

A project inbox is coming soon for corrections, source notes, and city-specific dope math. For now, the optional dictionary form is the best way to send local unit names, weights, prices, or slang.

What does this measure?
Read the transcript
What does this measure? Dope Math estimates the milligrams of fentanyl in the powder used per day. That is the number it puts first. It can give you and a provider a shared way to describe the scale of a habit. It is still an estimate, not a lab test, and not a measurement of what your body absorbs. The idea comes from published Los Angeles research. Researchers combined 509 aggregate drug-checking samples with detailed reports from 47 people, then ran a two-million-draw uncertainty model. The Los Angeles samples averaged about 12.5 percent fentanyl and fluorofentanyl, with a very wide aggregate range. The research was published in Drug and Alcohol Dependence and covered by The New York Times. Dope Math uses a simpler version of that idea. You enter a broad region, the local unit, the amount and frequency, and whether the supply seems weaker or stronger than the regional average. The tool converts that into milligrams of powder per day, applies an editable purity estimate, and shows estimated milligrams of fentanyl in the powder, plus a wide illustrative range. The purity starting points come from aggregate drug-checking research and public reports from Los Angeles, British Columbia, and Toronto. The broad other-U.S. value is an illustrative assumption. These averages move over time and cannot identify any specific bag. This result is not a methadone or buprenorphine dose. It does not calculate route, absorption, tolerance, or a safe amount. Medication dosing has to be individualized. But the estimate can make a provider conversation more concrete. Bring the number together with what you are actually feeling: withdrawal, cravings, and whether you feel stable. If you have had a break, say so, because tolerance can fall quickly. Estimated milligrams of fentanyl per day. A number for understanding your habit, hypothetically.