Size 000 empty capsules are the largest standard human two-piece capsule size. A locked Size 000 capsule is approximately 26.1 mm long, with an internal volume of about 1.37 mL and a typical guide fill range of 800–1600 mg, depending on powder density.
The actual weight that fits in a capsule depends on the bulk density, particle size and packing of the powder. Capsule size is fundamentally a volume measurement, so the same capsule can hold very different weights of different ingredients.
Size 000 Capsule Capacity
| Specification | Size 000 |
|---|---|
| Approx. volume | ~1.37 mL |
| Typical guide fill range* | 800–1600 mg |
| Relative size | largest standard human two-piece size |
*Approximate guide only. Actual fill weight depends on the material being filled and how densely it packs.
Easy Visual Size Reference

A size 000 capsule is about 26.1 mm long when locked. As a simple everyday reference, when laid lengthways, it is roughly as long as a UK 2p coin is wide. This comparison is only to help visualise the size; capsule dimensions should be used for accurate fitting.
What Is Size 000 Commonly Used For?
Size 000 can be used for self-filling powders and other suitable dry ingredients when its volume matches the required fill. The best size should be chosen from the physical volume of the ingredient rather than from milligrams alone.
How to Estimate Whether Your Powder Will Fit
If you know the powder’s bulk density in g/mL, multiply that value by the capsule volume (~1.37 mL) to estimate an approximate fill weight. Always allow for normal variation in powder flow and packing.
Size 000 vs Other Capsule Sizes
Capsule sizes become progressively smaller from 000 to 5. Use our complete Empty Capsule Size Guide to compare 000, 00, 0, 1, 2, 3, 4 and 5 in one table.
Size 000 · Size 00 · Size 0 · Size 1 · Size 2 · Size 3 · Size 4
Gelatin, HPMC, Pullulan or Delayed-Release?
The correct shell depends on more than size. Material, dietary preference and release profile can all matter. Pure Capsules supplies multiple capsule types and sizes, including gelatin, vegetarian HPMC, pullulan and selected delayed-release options.
Frequently Asked Questions
How many milligrams fit in a size 000 capsule?
A typical guide range is about 800–1600 mg, but there is no single guaranteed milligram capacity because powders differ in bulk density.
Is size 000 suitable for every powder?
No. Suitability depends on the powder volume, flow properties and your intended fill quantity. Test with the actual ingredient where possible.
Where can I compare all capsule sizes?
See the Pure Capsules empty capsule size chart for a full side-by-side comparison.
Shop Size 000 Empty Capsules by Material
Gelatin · HPMC · Pullulan · DRcaps®
Not sure which shell technology is right? Compare our empty capsule types or use the Capsule Size Calculator.
Ready to choose? Browse all empty capsules.






