Tools
Syringe dose calculator
Work out how many units to draw on an insulin syringe. Enter your label exactly as it is written, “mg per mL”, whatever the volume, and the dose your provider prescribed.
Please read first
This calculator is an arithmetic aid for people who already have a prescription and instructions from their provider. It is not medical advice and it never recommends a dose.
Type only the dose your provider prescribed, and always follow your provider’s instructions. If anything looks different from what you were told, stop and confirm with your provider or with us before you draw.
Everything stays on this page. What you type is not saved and is not sent anywhere.
Units to draw
Please fix the highlighted entries to see a result.
Approximate. Use this to double-check against your provider’s instructions, not instead of them.
Marks differ between syringe brands. Check the marks on your own syringe; this drawing is a guide.
How the calculation works
A standard insulin syringe (U-100) holds 100 units in every 1 mL, so 1 unit is 0.01 mL. We turn your label into mg per 1 mL, divide your dose by that to get the volume in mL, then multiply by 100 to get units.
Units = (dose in mg ÷ mg per mL) × 100
An example with made-up numbers
Label: 15 mg per 0.5 mL, so 15 ÷ 0.5 = 30 mg per mL. A 2.5 mg dose is 2.5 ÷ 30 = 0.0833 mL, which is 8.33 units (8.5 when rounded to the nearest half unit). This only shows the arithmetic. It is not a dose.
Why “per 0.5 mL” matters
Many calculators assume the label means “per 1 mL”. If your label says 15 mg per 0.5 mL, that is 30 mg in each 1 mL, twice as concentrated. Because you enter both the amount and the volume here, nothing is assumed.
Questions about your dose?
Our team is happy to go over your instructions with you. Call us at (656) 262-3529 or view availability.