What is the concentration of a 2 mg vial?

It depends on how much liquid is added: 2 mg ÷ mL added. With 1 mL it's 2 mg/mL (2,000 mcg/mL), with 2 mL 1 mg/mL (1,000 mcg/mL), and with 3 mL 0.667 mg/mL (666.7 mcg/mL).

How many units is 0.1 mg from a 2 mg vial?

On a U-100 syringe: 5 units with 1 mL added, 10 units with 2 mL and 15 units with 3 mL. This is a unit conversion, not a dose: scale it to the amount your prescriber or label gives you, or use the calculator.

How much water should I add to a 2 mg vial?

That comes from your prescriber, pharmacy instructions or the product label. The volume doesn't change how much is in the vial, only the concentration: more liquid means more units for the same amount, less liquid means fewer.

Does this calculator recommend a dose?

No. It only does arithmetic on the numbers you enter. The amount field starts empty on purpose, and Caliper never suggests an amount, a dilution or a schedule.

2 mg vial reconstitution calculator

The concentration math for a 2 mg vial with common diluent volumes, and a calculator with your vial size already filled in.

A 2 mg vial holds 2 mg however much liquid you add. The liquid only sets the concentration: 2 mg ÷ mL added = mg per mL. The table below is plain arithmetic for 1, 2 and 3 mL.

2 mg vial: concentration by volume of diluent added
Diluent added	mg per mL	mcg per mL	U-100 units per 0.1 mg
1 mL	2	2,000	5
2 mL	1	1,000	10
3 mL	0.667	666.7	15

Math only. These volumes are for illustration, not recommendations; use the volume your instructions give and the amount your prescriber or label gives.

Reconstitution calculator

Enter the numbers from your own vial, and pick the syringe in your hand. Check the U- number and size printed on the syringe box.

Concentration

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Draw volume

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Syringe units

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U-100 1 mL, holds 100

Draws in the vial

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1Concentration: 2 mg ÷ mL added mL = concentration
2Draw volume: amount in mg ÷ concentration = draw mL
3Syringe units: draw mL × 100 units per mL (U-100) = units

Math only, not dosing advice. Follow your prescriber or label. Real vials give slightly less than the full-draw count: a little liquid stays in the vial and needle. Your last setup is saved in this browser only; Clear removes it.

Save your vial in Caliper and it remembers the concentration and use-by date you entered, alongside your dose log. The calculator above is a browser tool and is not part of the app.

Save my vial in Caliper

Reading the 2 mg numbers

A 2 mg vial makes a fairly dilute solution: even with 1 mL added, every 0.1 mg takes 5 units on a U-100 syringe. Dilute solutions are easier to read in small amounts, but larger draws take more volume, which can be more than a 0.3 mL (30-unit) or 0.5 mL (50-unit) syringe holds. Check the full-draw count too: a small vial runs out faster.

“Units per 0.1 mg” is a scaling figure, the way a map has a scale. To get any amount, multiply: 0.5 mg is five times the 0.1 mg figure. Or enter your own amount in the calculator above, which also handles 0.3 mL and 0.5 mL U-100 syringes and U-50 and U-40 scales.

Start from what's actually in your vial. The label states the amount, and for research products the lab report (COA) may show a different net amount; if they differ, the concentration changes in proportion. Our COA guide explains what to look for.

FAQ

What is the concentration of a 2 mg vial?: It depends on how much liquid is added: 2 mg ÷ mL added. With 1 mL it's 2 mg/mL (2,000 mcg/mL), with 2 mL 1 mg/mL (1,000 mcg/mL), and with 3 mL 0.667 mg/mL (666.7 mcg/mL).
How many units is 0.1 mg from a 2 mg vial?: On a U-100 syringe: 5 units with 1 mL added, 10 units with 2 mL and 15 units with 3 mL. This is a unit conversion, not a dose: scale it to the amount your prescriber or label gives you, or use the calculator.
How much water should I add to a 2 mg vial?: That comes from your prescriber, pharmacy instructions or the product label. The volume doesn't change how much is in the vial, only the concentration: more liquid means more units for the same amount, less liquid means fewer.
Does this calculator recommend a dose?: No. It only does arithmetic on the numbers you enter. The amount field starts empty on purpose, and Caliper never suggests an amount, a dilution or a schedule.

Other vial sizes

Compounds sold in 2 mg vials

The math above is the same for any compound. These pages add compound-specific mixing and storage notes, with the calculator set to that compound's vial sizes.

Related guides

Updated October 17, 2026

For adults 18+. Educational math only, not medical advice. This page does not recommend any dose, dilution, syringe or compound. Always follow your prescriber's instructions and the product label, and ask a pharmacist if a number doesn't look right.