Capsule Sizes #000 to #5 Explained: Choosing the Right Size for a 100-Hole Capsule Filler
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The right capsule size for a 100-hole capsule filler is the smallest standard size (#000 to #5) that holds your full target dose at the density of your actual powder blend. Because the SciMed 100-hole machine is fixed-size, with plates precision-matched to one capsule size, getting this choice right before you order matters more than it does with interchangeable-plate equipment. This guide walks through the size chart, the volume-versus-weight trap, and a simple process for picking one size (or deciding you need two machines).
If you are still deciding between equipment types, our guides on how to choose a 100-hole stainless steel capsule filling machine and manual vs. automatic capsule fillers cover that ground. Here we focus only on size.
The capsule size chart: #000 to #5
Capsule sizes run backwards: the more zeros, the bigger the capsule, and higher numbers are smaller. The table below shows typical body diameter and fill figures for each of the 8 sizes the SciMed 100-hole machine is available in.
| Size | Body diameter | Typical fill volume | Typical fill weight* | Common use |
|---|---|---|---|---|
| #000 | 9.9 mm | 1.37 mL | ~1,100 mg | Herbal / Ayurvedic bulk formulations |
| #00 | 8.5 mm | 0.95 mL | ~750 mg | Nutraceuticals, high-dose vitamins |
| #0 | 7.6 mm | 0.68 mL | ~500 mg | Most common supplement size |
| #1 | 6.9 mm | 0.5 mL | ~400 mg | Vitamins, herbal blends |
| #2 | 6.4 mm | 0.37 mL | ~300 mg | Compounded prescriptions |
| #3 | 5.8 mm | 0.3 mL | ~240 mg | Compounded low-dose Rx |
| #4 | 5.3 mm | 0.21 mL | ~170 mg | Pediatric compounded Rx |
| #5 | 4.9 mm | 0.13 mL | ~100 mg | Low-dose pediatric Rx |
*Typical figures only. Actual fill weight depends on your powder's density and how it is tamped.
Volume is fixed; weight is not
The single most common sizing mistake is treating the milligram column as a guarantee. A capsule is a container of fixed volume. How many milligrams fit inside depends on the bulk density of what you put in it.
- Dense powders (many mineral salts, some granulated actives) pack more milligrams into the same volume, so you may get more than the typical figure.
- Light, fluffy powders (many dried herbs, leaf and root powders, some botanical extracts) pack fewer milligrams, so the same capsule may hold noticeably less than the chart suggests.
- Tamping increases how much fits. The machine ships with a powder tamping tool for uniform fill compression, but tamping has practical limits, and over-compressing can make closing difficult.
The practical takeaway: work out your size from your real blend, not from the chart alone.
A simple way to choose your size
Step 1: Define the dose per capsule
Start with the target weight of fill per capsule, including any excipients such as fillers or flow agents. If a product is dosed as several capsules, decide whether you would rather use fewer, larger capsules or more, smaller ones. Patient or customer preference (swallowability, number of capsules per serving) matters here.
Step 2: Measure the bulk density of your blend
Weigh a known volume of your final blend in a graduated cylinder. Weight divided by volume gives you an approximate bulk density in mg/mL. Many formulators also measure tapped density, which better reflects what happens after tamping. Your formulator or quality team will have a preferred method.
Step 3: Calculate the volume you need
Divide your target fill weight (mg) by the density (mg/mL). The result is the volume each capsule must hold.
Worked example: a 450 mg herbal fill with a measured density of 600 mg/mL needs about 0.75 mL. That rules out #0 (0.68 mL) and points to #00 (0.95 mL). The same 450 mg dose in a denser blend at 900 mg/mL needs only 0.5 mL, which a #1 (0.5 mL) holds with no headroom, so a #0 gives room to spare.
Step 4: Leave a margin
Choose a size that gives some headroom above the calculated volume. Batch-to-batch variation in raw materials can shift density, and a little margin keeps you from being stuck with a machine that is just too small.
Step 5: Run a hand test
Before committing, buy a small sample of empty capsules in the two closest candidate sizes and hand-fill a few with your blend, weighing each. This low-cost check confirms the math against real-world behavior.
Typical sizes by type of operation
- Compounding pharmacies: often work in the smaller range (#2 to #5) for low-dose and pediatric prescriptions, though larger sizes are also used.
- Supplement and nutraceutical brands: #0 is the most common supplement size, with #00 used for high-dose vitamins.
- Herbal and Ayurvedic producers: light botanical powders often push toward #00 or #000 to reach a meaningful dose per capsule.
- Academic and R&D labs: size depends on the study design; many choose a common size like #0 or #1 to match commercially available empty capsules.
What if you fill more than one size?
The SciMed 100-hole machine is fixed-size: each hole diameter is matched to one capsule size, selected at checkout. If you routinely fill several sizes, you have two options:
- One machine per size. Most operations dedicate one machine to each size for efficiency, and volume pricing is available on 3+ units.
- Size-specific plate sets. A full disassemble and swap of size-specific plates is possible, with plate sets sold separately at roughly $400–$600 per set.
If one size covers 80–90% of your volume, starting with a single machine in that size and adding a second later is a common approach.
Capsule materials and compatibility
Size is standardized across the industry, so a #0 capsule from one brand fits the same plates as a #0 from another. The machine works with hard-shell gelatin, HPMC (vegetable) and pullulan capsules, either empty or pre-locked. It is not designed for soft-gel capsules. Free-flowing powders work best; sticky or hygroscopic materials may need pre-processing, so consult a pharmaceutical formulator for challenging blends.
Machine specs relevant to sizing
- 100 capsules per fill cycle, with orienter included.
- 304 stainless steel, CNC-precision hole tolerance of ±0.02 mm.
- Throughput of roughly 1,200–2,000 capsules per hour with a trained operator.
- Manual operation; no electricity required for the base machine.
- 90-day defect warranty and 24-month replacement parts availability.
Not sure which size to order? Email sales@scimedstore.com or message us on WhatsApp at +1-669-265-9353 with your target fill weight and powder type, and we will help you narrow it down before you buy.
Frequently asked questions
Which capsule size is the most common?
Size #0 is the most common supplement size, with a typical fill volume of 0.68 mL, or roughly 500 mg depending on powder density.
Can one 100-hole machine fill different capsule sizes?
No. The SciMed 100-hole machine is fixed-size, with holes matched to one capsule size chosen at checkout. To fill another size you need a second machine or a separate size-specific plate set.
Why does my powder not reach the milligram figure on the size chart?
Capsule volume is fixed, but fill weight depends on your powder's density. Light, fluffy powders such as many herbs hold fewer milligrams per capsule than the typical chart figure.
Do capsules from different brands fit the same machine?
Yes, as long as they are the same size. Sizes #000 to #5 are industry-standard dimensions, and the machine works with hard-shell gelatin, HPMC and pullulan capsules.
How do I work out the right size for my formula?
Divide your target fill weight in milligrams by your blend's bulk density in mg/mL to get the volume needed, then choose the smallest size that holds that volume with some margin. Confirm with a small hand-fill test.