
Size 3 capsules are small empty capsules commonly used for:
- lower-dose supplements
- concentrated ingredients
- probiotics
- sensitive users
- easier swallowing
They are smaller than:
- size 2
- size 1
- size 0
- size 00
- size 000
making them a popular option for people who prefer smaller capsules.
This guide explains the approximate volume, dimensions, and powder capacity of size 3 empty capsules.
Size 3 Capsule Volume
The approximate internal volume of a size 3 capsule is:
0.30 ml
This smaller internal volume makes size 3 capsules suitable for lighter formulations and concentrated powders.
How Many mg Fit in a Size 3 Capsule?

The approximate powder capacity of a size 3 capsule is:
| Powder Type | Approximate Capacity |
|---|---|
| Light powders | 150–180 mg |
| Medium density powders | 200–260 mg |
| Dense powders | 300 mg |
Actual capacity depends on:
- powder density
- particle size
- moisture content
- powder compression
Size 3 Capsule Dimensions
| Measurement | Approximate Size |
|---|---|
| Length | 15.9 mm |
| Diameter | 5.8 mm |
| Volume | 0.30 ml |
Size 3 capsules are noticeably smaller than many standard supplement capsules.
What Are Size 3 Capsules Used For?
Size 3 capsules are commonly used for:
- probiotics
- concentrated extracts
- lower-dose supplements
- vitamins
- herbal powders
- sensitive users
They are often selected when:
- smaller capsules are preferred
- swallowing comfort is important
- lower doses are needed
Size 3 Capsule Capacity by Powder Density

Different powders can produce different fill weights inside the same capsule.
Low Density Powders
Examples:
- mushroom powders
- fluffy herbs
- botanical powders
Approximate fill:
- 150–180 mg
Medium Density Powders
Examples:
- vitamins
- nutritional blends
- amino acid powders
Approximate fill:
- 200–260 mg
High Density Powders
Examples:
- minerals
- dense extracts
- compact powders
Approximate fill:
- up to 300 mg
Size 3 vs Other Capsule Sizes

| Capsule Size | Approximate Capacity |
|---|---|
| 000 | 700–1400 mg |
| 00 | 500–950 mg |
| 0 | 300–700 mg |
| 1 | 250–500 mg |
| 2 | 180–370 mg |
| 3 | 150–300 mg |
| 4 | 100–210 mg |
Size 3 capsules are considered:
- small capsules
- suitable for lighter dosages
- easier to swallow than larger capsule sizes
Are Size 3 Capsules Easy to Swallow?

Yes. Size 3 capsules are generally considered easy to swallow due to their smaller dimensions.
They are often preferred for:
- sensitive users
- people who dislike large capsules
- probiotics
- lower-dose supplements
Gelatin vs HPMC Size 3 Capsules
Size 3 capsules are available in both:
- gelatin capsules
- HPMC vegetarian capsules
Gelatin Capsules
- traditional capsule material
- smooth texture
- widely used
HPMC Capsules
- vegetarian and vegan friendly
- plant-based
- suitable for clean-label supplements
Both types have similar capacities and dimensions.
Choosing Size 3 Capsules
Size 3 capsules may be suitable if you want:
- smaller capsules
- lower powder capacity
- easier swallowing
- compact supplement doses
If your formulation requires larger doses, you may prefer:
- size 2
- size 1
- size 0
- size 00
Frequently Asked Questions
How many mg fit in a size 3 capsule?
Typically around 150–300 mg depending on powder density.
What is the volume of a size 3 capsule?
A size 3 capsule has an approximate volume of 0.30 ml.
Are size 3 capsules easy to swallow?
Yes. Size 3 capsules are smaller than many standard capsule sizes and are generally easier to swallow.
Are vegetarian size 3 capsules available?
Yes. HPMC vegetarian size 3 capsules are widely available.
What are size 3 capsules commonly used for?
They are commonly used for probiotics, concentrated supplements, vitamins, and lower-dose formulations.
Related Pages
- Capsule Sizes Explained
- Capsule Size Chart
- Capsule Volume Chart
- Capsule Capacity Calculator
- Powder Density Calculator
- How Many mg Fit in a Capsule
- Size 000 Capsule Capacity
- Size 00 Capsule Capacity
- Size 0 Capsule Capacity
- Size 1 Capsule Capacity
- Size 2 Capsule Capacity
- Size 4 Capsule Capacity
