0.3, 0.5 and 1 mL syringe sizes
AT A GLANCE
U-100 syringes with capacities of 0.3, 0.5 and 1 mL hold up to 30, 50 and 100 marked units respectively. Capacity changes the maximum volume, not the U-100 relationship of 100 markings per mL.
For U-100 volume markings only. Keep mass units consistent: 1 mg = 1,000 mcg.
Same scale. Different capacities.
Bar length represents maximum volume, not the physical length of a syringe.
| Capacity | Maximum markings | Supported small divisions |
|---|---|---|
| 0.3 mL | 30 units | 0.5 or 1 unit |
| 0.5 mL | 50 units | 1 unit |
| 1 mL | 100 units | 1 or 2 units |
A worked example
0.5 mL × 100 = 50 markings. A 10-marking volume is still 0.1 mL in each of the three sizes.
Size is capacity; U-100 is the scale
The three common capacities hold 30, 50 or 100 markings on the U-100 scale. In each case, 10 markings still represent 0.1 mL. Terms such as “U-30” or “U-50” can confuse the barrel’s capacity with its scale, so this site labels capacity in mL.
Graduations vary by product
A barrel size does not uniquely determine its line spacing. For this tool, choose the actual 1- or 2-unit divisions on a 1 mL barrel, 1-unit divisions on a 0.5 mL barrel, or half-unit or 1-unit divisions on a 0.3 mL barrel. If your device differs, do not substitute the nearest option.
Match the actual equipment
The comparison explains what the markings mean, not which equipment you should use. Your prescriber or pharmacist can confirm a syringe that accommodates and clearly measures your prescribed volume. Needle length and gauge are outside this calculator’s scope.
What this conversion cannot tell you
Line spacing varies by product. This comparison does not select equipment, needle length or gauge for you.
Source: BD: syringe capacities and scale options. Supports the device scale and capacity context. Formula examples are arithmetic derived from the stated U-100 scale. Source checked 17 October 2026. This checks the cited device or unit context, not treatment suitability.
A blank calculator, transparent arithmetic and a close-up of your selected scale.
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