Capsule Size Guide
You might be asking yourself what is the best size capsule to choose when encapsulating powders. You are right to be asking yourself this question before starting a new formulation. It is crucial to think about this before starting to produce capsules and will save time and money in the long run when done correctly.
There are standard size capsules that are named by numerical values. They are numbered: 000, 00, 0, 1, 2, 3, 4 and 5. These sizes are the same for all types of Gelatin, HPMC and Pullulan. The majority of capsule filling machinery are manufactured to be compatible with these standard sizes.
We have put together this guide to help you choose the best size for your needs.
Below is an interactive chart to help you choose the best fit. Click on each size to highlight the specifications of that size capsule.
Capsule Size Chart
|Empty Capsule Size|
|Empty Capsule Weight (Gelatin)|
|Average Weight (mg)||158||143||123||107||99||78||61||48||38||28|
|Empty Capsule Weight (Vegetarian)|
|Average Weight (mg)||163||152||136||107||105||79||63||50||40||30|
|Empty Capsule Volume Capacity (ml)|
|Empty Capsule Weight Capacity by Formulation Density (mg)|
|Empty Capsule Overall Closed Length|
|Empty Capsule Individual Lengths (cap)|
|Empty Capsule Individual Lengths (body)|
|Empty Capsule External Diameter|
|Empty Capsule Quantity Per Case|
|Capsules per box||50,000||65,000||75,000||90,000||100,000||125,000||175,000||200,000||250,000||350,000|
How to Read the Capsule Size Chart
There is a lot of information on this table so here is a key on what each section means
- Capsule Weight - The weight of the capsule when empty in milligrams
- Volume Capacity - The volume of the inside of the capsule in millilitres
- Weight Capacity by Formulation - The weight capacity of the capsule (dependant on bulk density of formulation) in milligrams
- Overall Closed Length - The length of the capsule when it is fully closed and locked in millimetres
- Individual Lengths - Measures the body and the cap separately
- Tolerance - The acceptable variance in dimensions
Size Guide Video
We have put together this video to help you with capsule sizing.
Factors to Consider
When choosing a suitable size of capsule for your purposes there is a balance between the:
Volume of your mix
Ease of swallowing
Type of capsule being used
The required dosage comes down to how much of the active ingredient or ingredients is necessary for the product to be effective. You will need to decide how much of a dose you would like to be in each capsule e.g. 1000mg of Vitamin C
This will then be combined with excipients to help the product flow through the machine. Once mixed this is known as a “mix”.
You will need there to be the correct dose of ingredient within the mix in each capsule. If there is too much for one capsule you can either try to fit the powder in one capsules or you may want to consider spreading the dose over multiple capsules. E.g. rather than 1 #000 capsule splitting it over 3 #00.
Volume of the Mix
The volume of the mix will depend on the bulk density of the powders that make up your mix. We have a tool and guide on bulk density to help calculate the bulk density of your mix.
You need to know the bulk density of your mix so that you can work out how much active ingredient ends up in each capsule. It may result in you having to alter your mix slightly or spread the dose over more than one capsule.
Ease of Swallowing
Sometimes the sizes can be selected simply by the physical size of the capsule. For example when choosing a capsule for a child or an animal who might not be able to swallow larger capsules.
The reason that size 00 and size 0 are the most commonly used capsules in manufacturing is that they have adequate volume for a lot of mixes as well as being easy for humans to swallow.
Type of Capsule
Certain capsules such as Pullulan are only available in certain sizes. Determining the type of capsule you would like to produce may dictate your choice.
We have created this table to show the different capsules available for Geltain, HPMC and Pullulan.
To get a feel for the size of capsules you can use this scale chart to see them next to one another. On the left is millilitres and the right inches.
What is the most popular size capsule?
The most commonly used capsule is size 00. Below is a scale of size 0 and 00 capsules next to common coins to show their scale.
What Do the Capsule Numbers Mean?
Capsule sizes can seem counterintuitive as smaller sized capsules have higher numbers than larger capsules.
e.g. a # 5 capsule is smaller than a #4 capsule
A “000” (triple zero) capsule is the largest size available. In cases where capsule sizes are indicated with "0" names, 000s are the largest, while 0s are smaller.
#000 capsules sometimes referred to as "triple zero" are the largest size of standard capsules.
- The volume of a size 000 is 1.37ml
- The overall length of the capsule is 26.1mm
- The external diameter of the cap is 9.91mm
- A full box or case of 000 hard caps contains 50,000 capsules
#00 capsules sometimes referred to as "double zero" are the most commonly used capsules for supplements and medicines.
- The volume of a size 00 is 0.9ml
- The overall length of the capsule is 23.4mm
- The external diameter of the cap is 8.56mm
- A full box or case of 00 hard caps contains 75,000 capsules
#0 capsules sometimes referred to as "single zero" are the second most popular size of capsule after #00.
- The volume of a size 0 is 0.68ml
- The overall length of the capsule is 21.6mm
- The external diameter of the cap is 7.64mm
- A full box or case of 0 hard caps contains 100,000 capsules
#1 capsules are also commonly used and are slightly smaller than size zero capsule.
- The volume of a size 1 is 0.48ml
- The overall length of the capsule is 19.4mm
- The external diameter of the cap is 6.96mm
- A full box or case of 1 hard caps contains 125,000 capsules
#2 capsules are not as commonly used in food supplements but more so in pharmaceutical manufacturing.
- The volume of a size 2 is 0.36ml
- The overall length of the capsule closed is 17.6mm
- The external diameter of the cap is 6.39mm
- A full box or case of 2 hard caps contains 175,000 capsules
#3 capsules are smaller than size 2 and are not very commonly used due to their smaller overall volume.
- The volume of a size 2 is 0.27ml
- The overall length of the capsule closed is 15.7mm
- The external diameter of the cap is 5.85mm
- A full box or case of 3 hard caps contains 200,000 capsules
#4 capsules are the second smallest capsule variety. The are not used very often and are usually reserved for specialised medicines.
- The volume of a size 4 is 0.2ml
- The overall length of the capsule closed is 14.3mm
- The external diameter of the cap is 5.33mm
- A full box or case of 4 hard caps contains 250,000 capsules
#5 capsules are the smallest standard capsule size. They are predominantly used in pharmaceutical medicines rather than supplements.
- The volume of a size 5 is 0.13ml
- The overall length of the capsule closed is 11.1mm
- The external diameter of the cap is 4.91mm
- A full box or case of 5 hard caps contains 350,000 capsules
Do You Already Have a Capsule Filler?
Sometimes the size is dictated by the encapsulation solution you have available. For example a ProCap only comes in #00 however our capsule filling machinery has change tooling for all standard sizes.
If you are unsure then feel free to purchase a small quantity to sample. You can order 500 or 1000 before committing to a larger purchase.
If you are still struggling with which size is best for you please feel free to get in contact with us.