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General product information, not medical advice. Always follow the labelling and instructions for use of the product in your hands.
Pharmaceutical injection vials are sized by an “R” designation (2R, 10R, 20R and so on) defined in ISO 8362-1, and the number is not the capacity in millilitres. A 10R vial, for example, has a brimful (overflow) capacity of 13.5 ml, not 10 ml. The chart below lists all 12 formats from 2R to 100R with capacity, outer diameter, total height and approximate mass.
Vial size chart (2R to 100R)
Values are copied from the SCHOTT Pharma datasheet “Core Vials in StandardLine quality” (document 40141, 02/2026), table “ISO 8362-1 Dimensions, brimful capacity and mass”, checked 2026-10-30. This is one manufacturer’s reproduction of the ISO table for its own StandardLine product, not the text of the standard.
| Size designation | Overflow (brimful) capacity, ml | Outer diameter d1, mm | Total height h1, mm | Mass, g (approx.) |
|---|---|---|---|---|
| 2R | 4 | 16 | 35 | 4.4 |
| 3R | 5 | 16 | 40 | 5.5 |
| 4R | 6 | 16 | 45 | 5.7 |
| 6R | 10 | 22 | 40 | 7.9 |
| 8R | 11.5 | 22 | 45 | 8.7 |
| 10R | 13.5 | 24 | 45 | 9.5 |
| 15R | 19 | 24 | 60 | 12.0 |
| 20R | 26 | 30 | 55 | 16.2 |
| 25R | 32.5 | 30 | 65 | 18.9 |
| 30R | 37.5 | 30 | 75 | 21.9 |
| 50R | 62 | 40 | 73 | 34.5 |
| 100R | 123 | 47 | 100 | 60 |
Check your product’s labelling. The chart describes the SCHOTT StandardLine formats listed in that datasheet. Another maker’s vial, a vial labelled in millilitres, or a different product line may differ. Use the manufacturer’s drawing or the label for the vial you actually have.
How to read the chart
What does the “R” size designation mean?
It is the format name from ISO 8362-1, the standard the manufacturer cites for its vial formats. The SCHOTT datasheet states that its formats follow the current version of ISO 8362-1 and that its Type I borosilicate glass is made according to ISO 8362-2. The letter and number identify a format with set dimensions; they are not a volume.
What is overflow (brimful) capacity?
The datasheet column is headed “Overflow capacity of injection vial”. It is the volume the vial holds when filled to the brim. It is therefore larger than any normal fill volume, and it is not a statement of how much product the vial is intended to contain.
Which dimensions are shown?
d1 is the outer diameter of the vial body and h1 is the total height, both in millimetres. The datasheet table carries further dimensions (neck, collar, bottom thickness and others) that are omitted here.
How to measure a vial
To match a vial to the chart, measure the outer diameter of the body and the total height with a caliper and compare them with the d1 and h1 columns. Diameter alone is not enough, because several formats share it: 2R, 3R and 4R are all 16 mm; 6R and 8R are 22 mm; 10R and 15R are 24 mm; 20R, 25R and 30R are 30 mm. Height separates them (for 3R and 4R, 40 mm against 45 mm). The table lists nominal values, so compare against the manufacturer’s drawing if a measurement sits slightly off.
Equivalence notes
R size against millilitres
Take the capacity from the table, not from the number in the name. From the chart: 2R is 4 ml, 6R is 10 ml, 10R is 13.5 ml, 20R is 26 ml and 100R is 123 ml.
Neck size
The same datasheet gives a neck outer diameter (d2) of 13 mm for the 2R to 15R formats and 20 mm for the 20R to 100R formats. For the stopper material side, see the guide to butyl rubber.
Common mix-ups
- Overflow capacity against fill volume. The chart gives the brimful figure only. It does not say how full a vial of a given product is filled.
- R number against millilitres. 10R is not a 10 ml vial. 20R is not a 20 ml vial.
- Diameter alone. Formats that share a diameter differ in height and capacity, as in the measuring section above.
- Injection vials against other vials. This chart covers glass injection vials only. For other containers, see what a cryovial is and dental syringe cartridge sizes.
Frequently asked questions
What does 10R mean on a vial?
It is the ISO 8362-1 format designation. In the SCHOTT datasheet table, 10R has a brimful capacity of 13.5 ml, an outer diameter of 24 mm and a total height of 45 mm.
What is the size of a 20R vial?
Per the same table, 20R has a brimful capacity of 26 ml, an outer diameter of 30 mm, a total height of 55 mm and a mass of about 16.2 g.
What is the smallest and largest format in the chart?
The table runs from 2R (4 ml brimful capacity) to 100R (123 ml). SCHOTT’s vials page states that its formats range from 2R up to 100R.
What glass are these vials made of?
The datasheet describes Type I borosilicate glass with high chemical resistance, with hydrolytic resistance tested according to the pharmacopoeias (USP, Ph. Eur.) and ISO 4802-2. For the glass class itself, see Type I borosilicate glass.
Sources
- SCHOTT Pharma, “Core Vials in StandardLine quality”, datasheet 40141, 02/2026 (table “ISO 8362-1 Dimensions, brimful capacity and mass”). Checked 2026-10-30.
- SCHOTT Pharma, Core Vials product page and vials overview. Checked 2026-10-30.
- ISO 8362-1, the standard the SCHOTT datasheet names for its vial formats: ISO catalogue search for ISO 8362-1. The table above is the manufacturer’s reproduction, not the standard’s text. Checked 2026-10-30.
