Choosing empty capsules comes down to two decisions: the size, which sets how much the capsule holds, and the material, which is either gelatin or vegetarian. Get both right and your product is easy to fill, easy to swallow, and suited to the people who will take it. This guide explains empty capsule sizes from 000 down to 5, how gelatin and vegetarian capsules differ, and how to choose for a supplement blend, a herbal formula, or a dispensary.
A note before we start: this is packaging guidance, not dosage or medical advice. Your fill formulation, dose, and any regulatory requirements are yours to confirm.
What are empty capsules?
Empty capsules are two-piece hard shells, a shorter cap and a longer body, that you fill yourself and then join together. They are the standard format for powders and granules, whether you are compounding in a dispensary or packing your own herbal blend.
They are different from soft capsules. Hard-shell capsules hold dry, powdered ingredients, while soft capsules are made in one piece and used mainly for oils and liquids. If you are filling your own capsules by hand or with a tray, you are almost always working with two-piece hard shells.
Empty capsule sizes explained
Capsule sizes run on a fixed scale. Confusingly, the numbers get larger as the capsule gets smaller, so 000 is the biggest common size and 5 is the smallest. Here are the standard sizes with their approximate capacity.
| Size | Approx. volume | Approx. powder capacity |
|---|---|---|
| 000 | ~1.37 mL | ~600 to 1000 mg |
| 00 | ~0.91 mL | ~400 to 800 mg |
| 0 | ~0.68 mL | ~300 to 550 mg |
| 1 | ~0.50 mL | ~300 to 400 mg |
| 2 | ~0.37 mL | ~200 to 300 mg |
| 3 | ~0.30 mL | ~150 to 250 mg |
| 4 | ~0.20 mL | ~100 to 150 mg |
| 5 | ~0.13 mL | ~60 to 100 mg |
Treat the powder capacity as a range, not a fixed figure, because it depends on how dense your powder is. A heavy mineral powder weighs far more in the same capsule than a light, fluffy herb. The volume is fixed; the weight it holds is not.
How to choose a size
For most powdered supplements and herbal blends, size 00 and size 0 are the workhorses. Size 00 holds a generous dose and is the most common choice. Size 0 holds a little less and is slightly easier to swallow, which matters if your customers find large capsules difficult. Step up to 000 only when a dose genuinely needs it, and be aware that 000 is a large capsule to swallow.
The reliable way to choose is to test-fill. Take your actual powder, fill a few capsules of two candidate sizes, and weigh them. That tells you the real fill weight for your blend, which no chart can, and it confirms the capsule swallows comfortably.
Gelatin vs vegetarian capsules
The material is the second decision, and it is often decided by who your customer is.
| Gelatin | Vegetarian (HPMC) | |
|---|---|---|
| Made from | Animal collagen | Plant cellulose (hydroxypropyl methylcellulose) |
| Suits | General use, cost-sensitive runs | Vegan, vegetarian, halal, kosher audiences |
| Cost | Usually lower | Usually a little higher |
| Moisture | Good barrier; can get brittle if too dry | More tolerant of moisture-sensitive fills |
Gelatin capsules are the long-standing standard: widely available, economical, and a good moisture barrier for most powders. Vegetarian capsules, introduced in the late 1980s and made from cellulose, are the choice when your audience avoids animal products or follows dietary rules, and they tend to handle hygroscopic or moisture-sensitive ingredients well.
There is no single right answer. If your brand is built around plant-based or faith-based dietary needs, vegetarian is effectively required. If cost is the priority and your audience has no such need, gelatin does the job.
Filling, fill weight, and equipment
How you fill depends on volume. A handful of capsules can be filled by hand, but a capsule filling tray or machine gives you consistent fill weight and far more speed once you are making batches. Consistency matters: customers and, where relevant, regulators expect each capsule to hold close to the same amount.
Whichever method you use, weigh capsules across a batch to confirm your fill weight stays in range. Powder that is not tamped evenly, or that varies in density between lots, will change your fill, so check rather than assume.
Consistency is not just good practice, it is what your label promises. If the pack states a set amount per capsule, each capsule needs to be close to it, so build a quick weight check into your filling routine and keep a note of the fill weight for each blend and lot. That record also makes reordering and troubleshooting easier later, because you can see at a glance which size and fill weight worked for a given formula.
Storage and shelf life
Keep empty and filled capsules cool and dry. Gelatin is sensitive to humidity and heat, and can turn brittle in very dry air or soft and tacky in damp, warm conditions. Vegetarian capsules are generally more tolerant of humidity swings. Store your stock away from direct heat and moisture, and your capsules stay easy to fill and join.
Joined vs separated capsules
Empty capsules come two ways. Separated capsules arrive with the cap and body apart, ready for you to fill and then join, which is what you want if you are filling your own product. Joined capsules arrive already closed, which suits buyers who need the empty shells pre-assembled. If you are packing a powder blend yourself, order separated capsules so you are not pulling every one apart before you start.
How many capsules will you need?
Work backwards from the dose. Multiply the capsules per serving by the servings per day, by the days of supply, by the number of units you plan to sell, then round up to a sensible order lot. Add a margin for filling errors and the odd cracked shell, because a few will not survive the process. It is better to hold a modest surplus than to stop a filling run halfway because you counted too tight.
Common mistakes when buying empty capsules
- Choosing a size by weight alone. The volume is fixed, but the weight it holds depends on your powder’s density. Test-fill and weigh.
- Overlooking swallowability. A 000 holds a large dose but is a large capsule to swallow. Two smaller capsules are sometimes the better answer.
- Ignoring dietary needs. Gelatin will turn away a vegan, halal, or kosher customer. Match the material to your audience.
- Storing in humidity. Damp, warm storage softens gelatin. Keep stock cool and dry.
- Buying far more than you will use. Capsules, gelatin especially, do not last forever. Order to a realistic horizon.
Buying empty capsules in Canada
When you know your size and material, you can order empty capsules in the common sizes, alongside the rest of our pharmacy supplies, with low minimums so a first run does not mean a pallet. Everything ships from Surrey, British Columbia, which keeps lead times short for Canadian makers and dispensaries.
The short version
Two decisions, in order. Pick the size by dose and powder density, starting from size 00 or 0 for most blends and test-filling to confirm the real fill weight. Then pick the material by your audience: vegetarian for plant-based or faith-based needs, gelatin for general, cost-sensitive use. Store cool and dry, weigh a sample of each batch, and confirm your own formulation and any regulations before you sell.
By the Vials.ca team. Vials.ca is the storefront of Hemkund Remedies Inc., a Surrey BC packaging supplier that ships empty capsules, pharmacy vials, and pharmacy supplies to Canadian dispensaries and makers. Published 2026-08-12. This article is packaging guidance, not medical or dosage advice.