Capsule size guide
Size 4 empty capsules for bulk supply
Size 4 is the smallest standard size we supply. It is used for very low fill weights, where precision and a small capsule matter more than capacity.
Size 4, drawn to scale (white cap, clear body).
Size 4 fill weight by powder density
| 0.4 g/mL | 0.6 g/mL | 0.8 g/mL | 1.0 g/mL | 1.2 g/mL |
|---|---|---|---|---|
| 84 mg | 126 mg | 168 mg | 210 mg | 252 mg |
Typical uses for size 4 capsules
- Very low-dose formulations
- Potent pharmaceutical actives
- Highly concentrated extracts
- Products that need the smallest standard capsule
For very small doses, check fill-weight variation on your own equipment before committing to a large order.
Compare with neighbouring sizes
Size 4 capsules: questions
How much powder does a size 4 capsule hold?
A size 4 capsule has a typical volume of 0.21 mL. That is roughly 126 mg of powder at a tapped density of 0.6 g/mL, 168 mg at 0.8 g/mL and 210 mg at 1.0 g/mL. Actual fill weight depends on your blend and filling machine.
What are the dimensions of a size 4 capsule?
Typical closed length is 14.3 mm, with a cap diameter of 5.31 mm and a body diameter of 5.05 mm. Exact dimensions and tolerances are on the product specification sheet sent with your quote.
Which capsule types are available in size 4?
Capsules Hub supplies size 4 as: Gelatin capsules, HPMC (hypromellose) capsules. Custom colours and printing are available on request.
Can I buy size 4 capsules in small quantities?
No. Capsules Hub supplies empty capsules in bulk cartons only, to manufacturers who fill their own formulations.
Ready to source size 4 capsules? Tell us the material, colours and quantity and we will reply with bulk pricing and availability.
Request a bulk quote Open the capsule builder