Turn the numbers on a CBD oil label into mg per ml, per drop and per serving. This is label math only: we don't recommend a dose.
Total CBD on the label divided by the bottle size. Find your bottle, read across.
| Label strength | 15 ml bottle | 30 ml bottle | 60 ml bottle |
|---|---|---|---|
| 250 mg | 16.7 mg/ml | 8.3 mg/ml | 4.2 mg/ml |
| 500 mg | 33.3 mg/ml | 16.7 mg/ml | 8.3 mg/ml |
| 750 mg | 50 mg/ml | 25 mg/ml | 12.5 mg/ml |
| 1,000 mg | 66.7 mg/ml | 33.3 mg/ml | 16.7 mg/ml |
| 1,500 mg | 100 mg/ml | 50 mg/ml | 25 mg/ml |
| 2,000 mg | 133.3 mg/ml | 66.7 mg/ml | 33.3 mg/ml |
| 3,000 mg | 200 mg/ml | 100 mg/ml | 50 mg/ml |
For a 30 ml bottle. One drop is about 0.05 ml; a full dropper is usually about 1 ml. Droppers vary, so treat these as estimates.
| Label strength (30 ml) | 1 drop (0.05 ml) | Half dropper (0.5 ml) | Full dropper (1 ml) |
|---|---|---|---|
| 250 mg | 0.42 mg | 4.2 mg | 8.3 mg |
| 500 mg | 0.83 mg | 8.3 mg | 16.7 mg |
| 750 mg | 1.25 mg | 12.5 mg | 25 mg |
| 1,000 mg | 1.67 mg | 16.7 mg | 33.3 mg |
| 1,500 mg | 2.5 mg | 25 mg | 50 mg |
| 2,000 mg | 3.33 mg | 33.3 mg | 66.7 mg |
| 3,000 mg | 5 mg | 50 mg | 100 mg |
The big number on most oil labels (500 mg, 1,000 mg) is the CBD in the whole bottle. Divide it by the bottle size in ml to get mg per ml, then multiply by your serving size. Some labels also print mg per serving; check which serving size it assumes.
Full-spectrum keeps the plant's other cannabinoids, including some THC. Broad-spectrum removes THC; isolate is CBD alone. That label word decides whether the THC limits below matter to you.
From December 11, 2026, federal law caps finished hemp products at 0.4 mg of total THC per container, and most full-spectrum bottles are far above it. Run the lab report through the total THC calculator.
A trustworthy label points to a batch lab report (COA). Its CBD result should be close to the label; if it is far off, the mg per serving here will be off by the same amount.
The FDA has approved one CBD drug, Epidiolex, a prescription medicine for seizures linked to Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex.
The FDA says CBD products that have not gone through its review have not been evaluated for whether they work, what the proper dosage may be, how they interact with other drugs, or whether they have dangerous side effects. That is why we do the math and leave the dose to a doctor or pharmacist.
Under federal food and drug law, CBD is excluded from the definition of a dietary supplement, and it can't be added to food sold across state lines.
Open these official sources, with links, on our verification page →
General information, not legal or medical advice. The calculators work only from the numbers you enter.
Divide the total CBD on the label by the bottle size. A 1,000 mg bottle of 30 ml holds about 33.3 mg per ml, so a 0.5 ml serving is about 16.7 mg.
A dropper drop is about 0.05 ml, so one drop holds the mg per ml × 0.05. In a 1,000 mg, 30 ml bottle that is about 1.7 mg per drop. Droppers vary, so treat it as an estimate.
We don't recommend doses. This page only does the label math. Ask a doctor or pharmacist, especially if you take other medicines.
Usually not. Most oil labels show the total CBD in the whole bottle. Check for a separate "per serving" line and the serving size in ml.
Full-spectrum oil keeps the plant's other cannabinoids, including some THC. Broad-spectrum removes the THC but keeps other compounds. Isolate is CBD alone. The difference matters for the THC limits, not for this math.
The FDA has approved one CBD medicine, Epidiolex, a prescription drug for certain seizure disorders. It says store-bought CBD products have not been evaluated for whether they work, the proper dosage, or how they interact with other drugs.
That depends on your state and on how much THC the product holds. Check your state on the CBD law map, and use the total THC calculator for the federal 0.4 mg cap that starts December 11, 2026.