Fill weight per serving (mg)All powder in one serving: actives plus fillers and flow agentsTapped bulk density (g/mL)From your maker or ingredient spec sheet; see below to measure itMost capsules per servingLargest capsule sizeSize 000 is hard for many people to swallow

Smallest fit2 × size 00

Each capsule 73% full (400 mg of 546 mg capacity).

Size	Volume	Holds	Capsules per serving	Fill
Size 000	1.37 mL	822 mg	1	97%
Size 00	0.91 mL	546 mg	2	73%
Size 0	0.68 mL	408 mg	2	98%
Size 1	0.50 mL	300 mg	3	89%
Size 2	0.37 mL	222 mg	4	90%
Size 3	0.30 mL	180 mg	5	89%
Size 4	0.21 mL	126 mg	7	91%

Capacity = capsule volume × tapped bulk density, the same basis as Capsugel's size chart. Real fill weights vary with the blend and the filling machine; confirm with your manufacturer's trial fill.

Capsule capacity by size and powder density

Maximum fill per capsule in mg. Volumes are for standard hard gelatin capsules; veggie (HPMC) capsules of the same size hold about the same.

Size	Volume	0.4 g/mL	0.6 g/mL	0.8 g/mL	1.0 g/mL
Size 000	1.37 mL	548	822	1,096	1,370
Size 00	0.91 mL	364	546	728	910
Size 0	0.68 mL	272	408	544	680
Size 1	0.50 mL	200	300	400	500
Size 2	0.37 mL	148	222	296	370
Size 3	0.30 mL	120	180	240	300
Size 4	0.21 mL	84	126	168	210

A size 00 capsule holds about 730 mg of a powder at 0.8 g/mL, but only about 360 mg of a fluffy extract at 0.4 g/mL. That's why two formulas with the same label weight can need different capsule counts.

Getting your blend's density

Use the tapped bulk density, the density after the powder has settled, because that is closest to how powder packs into a capsule.

Ask for it. Ingredient suppliers often list bulk and tapped density on the spec sheet, and your manufacturer can measure the finished blend.
Measure it. Pour powder into a graduated cylinder, tap it on the bench until the level stops dropping, then divide the powder's weight in grams by its volume in mL.
Measure the whole blend. Fillers and flow agents change the density too, so measure or ask about the final mix, not each ingredient alone.

When the formula doesn't fit

More capsules per serving. Two or three capsules per serving is common for higher-dose formulas.
A larger size. Size 000 holds the most, but it is large to swallow, so many brands stop at 00.
A denser blend. A manufacturer can sometimes granulate or compact a fluffy blend, or source a denser form of an ingredient.
A different format. High-dose formulas often work better as a powder, tablet or softgel. See gummies vs capsules for how formats compare on minimums and lead times.

Next steps

Once you know the capsule size and count, take it to a maker. Browse capsule manufacturers, work out your first run's raw material with the supplement batch planner, then request a quote. Ask the manufacturer for a trial fill on its own machines before you print labels: real fill weights vary with the blend and the equipment.

Capsule Size Calculator

Capsule capacity by size and powder density

Getting your blend's density

When the formula doesn't fit

Next steps

Sources