Herb Affair tools / 02
Compare empty capsule sizes 000 through 5 by real dimensions, fill volume and estimated powder capacity. Choose a powder, enter your target dose, and use the on-screen scale to find the smallest capsule size that fits your formula.
A bank card is 85.6 mm wide. Once it matches, the capsules are life-size on your screen.
Standard two-piece capsule specifications. Gelatin and vegetarian HPMC shells share the same external dimensions for each standard size. Actual fill weight varies with powder density.
| Size | Volume mL | Length mm | Length in | Diameter mm | Diameter in | Typical fill mg (1.0 g/mL) |
|---|---|---|---|---|---|---|
| 000 | 1.37 | 26.14 | 1.029 | 9.91 | 0.39 | 1370 |
| 00 | 0.95 | 23.3 | 0.917 | 8.53 | 0.336 | 900 |
| 0 | 0.68 | 21.7 | 0.854 | 7.65 | 0.301 | 680 |
| 1 | 0.5 | 19.4 | 0.764 | 6.91 | 0.272 | 480 |
| 2 | 0.37 | 18.0 | 0.709 | 6.35 | 0.25 | 360 |
| 3 | 0.3 | 15.9 | 0.626 | 5.83 | 0.23 | 270 |
| 4 | 0.21 | 14.3 | 0.563 | 5.32 | 0.209 | 200 |
| 5 | 0.13 | 11.1 | 0.437 | 4.91 | 0.193 | 130 |
The smallest capsule that will hold a given dose. Choosing the smallest workable size makes the capsule easier to swallow and cheaper per dose.
| Dose | Light 0.35 g/mL | Medium 0.55 g/mL | Dense 0.75 g/mL |
|---|---|---|---|
| 100 mg | 3 | 4 | 4 |
| 200 mg | 0 | 2 | 3 |
| 300 mg | 00 | 0 | 1 |
| 400 mg | 000 | 00 | 0 |
| 500 mg | — | 00 | 0 |
| 600 mg | — | 000 | 00 |
| 750 mg | — | 000 | 000 |
| 1000 mg | — | — | 000 |
Size 00 is one of the most widely used capsule sizes for home supplement making. It offers a practical balance of capacity and swallowability and is compatible with the CAPSULE-IT filling machine.
No. The CAPSULE-IT Original and Pro Series 400 work with sizes 000, 00, 0, and 1 only. Sizes 2 through 4 need to be filled by hand or with another compatible filling method.
Capsule size itself is not the main factor in shell dissolution. Capsule material can affect dissolution behavior, which is why gelatin and vegetarian HPMC shells may perform differently.
Size 00 holds 0.95 mL while size 0 holds 0.68 mL in the standard specifications used by this chart. If your dose sits between the two, size 00 gives you more room.
Yes. The standard sizing system is shared across both materials. A size 00 vegetarian capsule and size 00 gelatin capsule use the same basic dimensions and capacity; the shell material is what changes.
Start with your target dose and the powder's bulk density. Dose in grams divided by density in g/mL gives you the volume you need. You can also use the interactive dose calculator above to estimate the smallest workable capsule size.
You can physically use both materials in the same batch when the capsule sizes match, but keeping one shell material per batch usually makes the process and labeling more consistent.
Size 000 is the largest standard capsule shown in this chart at 1.37 mL. Capsule numbering runs in reverse, so the capsules become smaller as the number increases.
First-time capsule purchasers typically pick size 00 because it looks standard. Then they find out their dose does not fit, or their powder is too fluffy, or their capsule filler only accepts certain sizes. One wrong assumption and you are sitting on 1,000 capsules you cannot use.
We have been helping people make their own supplements at home since the beginning, trusted by over 100,000 customers who choose to know exactly what is in their supplements rather than take a label at face value.
In this guide, we’ll examine how to use a capsule size chart to match your dose correctly, how to choose between gelatin and vegetarian options, and how capsule size affects what your filling machine can do.
A capsule size chart tells you volume. What it does not tell you is how much of your specific powder actually fits inside that volume. That depends on density, which varies widely among powders. Turmeric packs tightly. Lion's mane mushroom powder is light and airy. The same-size capsule can hold substantially different weights depending on the powder.
This matters when you are working backward from a target dose. Say you want 500mg of magnesium glycinate per capsule. At its typical bulk density, a size 00 capsule may be a reasonable fit. A lighter powder such as lion's mane may require a larger capsule to reach a similar weight target.
Start with your target dose in milligrams. Then look up the bulk density of your specific powder. From there, use the empty capsule size chart above to find the volume in milliliters. The math is straightforward: dose in grams divided by density in g/mL equals the volume you need. Pick the capsule size that meets or slightly exceeds that number.
Any capsule size guide worth reading will tell you the size numbers are the same across both capsule types. What most skip over is that the material affects how the capsule behaves during filling, storage, and digestion. Here is what actually differs between the two:
Gelatin and HPMC capsule shells can differ in rupture and dissolution behavior. Research comparing hard gelatin and hypromellose capsules found measurable differences in shell rupture time under dissolution testing (Drug Development and Industrial Pharmacy, 2007). If timing is important to your formulation, capsule material is worth considering before you choose.
Humidity can affect capsule shell properties during storage and filling. Research has evaluated how gelatin and HPMC shells respond under humidity conditions (Pharmaceutics, 2025). Herb Affair's vegetarian capsule information also covers HPMC capsules and their use for home capsule filling, while additional research discusses HPMC capsules for moisture-sensitive products (Pharmaceutical Science and Technology, 2021).
Gelatin is animal-derived, while HPMC is plant-based. That distinction can matter for vegetarian or vegan preferences and for other sourcing requirements. Research has also examined alternative capsule materials and dietary considerations (DARU Journal of Pharmaceutical Sciences, 2017). Our Gelatin Capsule Information page provides a complete material breakdown.
Not every capsule size works with every filling machine, and assuming otherwise is one of the more frustrating mistakes to make mid-batch. The capsule size has to match the tray hole size, or it will not fill cleanly. Here is what to confirm before you order:
Our CAPSULE-IT Original and Pro Series 400 work with sizes 000, 00, 0, and 1. Before ordering, cross-reference the capsule capacity chart above to confirm your dose fits within the volume those sizes offer. Sizes 2 through 4 are not compatible with these machines and would need to be filled by hand or with another compatible filling method.
Standard capsules come joined at the cap and body. Pre-separated capsules come already pulled apart, which is how a filling machine needs them loaded. Using joined capsules in a machine tray adds an extra separation step and slows the process. Our guide on Why You Should Fill Your Own Capsules covers how to set up an efficient filling workflow from the start.
The body loads downward into the tray. The cap gets pressed down to close after filling. If the capsule does not match the tray size, loading and closing will not work correctly. Always confirm the size match before starting a batch.
Picking the right capsule comes down to three things working together: your target dose, your powder's density, and the equipment you are filling with. Get those three aligned and the rest of the process is straightforward. Material choice, whether gelatin or vegetarian, adds another layer worth thinking through depending on your diet, your environment, and how much the sourcing of every component matters to you.
We carry the capsules, powders, and filling machines to put all of this into practice at home. Use the pill capsule size chart above and our full capsule lineup when you are ready to act on what you have learned here.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.