Free tool
Reconstitution Calculator
Pick your measure, enter what’s in the vial and how much water you added, then the amount you want. The mark to draw to appears instantly.
Read this first
This is a maths tool, nothing more. It shows how a known amount of liquid divides across the marks on a 1 mL or 3 mL measure once a vial has been mixed. It is not an instruction to use any product, a recommendation of any amount, or medical advice. It doesn’t know what is in your vial and doesn’t need to. You enter every figure, and you are responsible for checking them.
How it works
The calculation, explained
Three steps, and you can check each one by hand.
- 01
Concentration
Divide the amount in the vial by the water you add. That tells you how much is in each millilitre. 5 mg in 2 mL is 2.5 mg/mL, or 2,500 mcg/mL.
- 02
Volume
Divide the amount you want by the concentration. That’s how many millilitres to draw. 250 mcg ÷ 2,500 mcg/mL is 0.1 mL.
- 03
The mark
A 1 mL measure has 100 unit marks per millilitre, so multiply the volume by 100. 0.1 mL is 10 units. A 3 mL measure is marked in millilitres, so you read the volume straight off. Either way the marks measure volume, not what’s in it: the same 10 units holds a different amount depending on how much water you added.
Reading the marks
Read the printed numbers, not the lines. On a 1 mL measure every 10 units is 0.1 mL, so 10 units sits on the first big number. On a 3 mL measure each small line is 0.1 mL.
mg or mcg?
1 mg = 1,000 mcg. Vials are usually labelled in mg and amounts are often written in mcg. Check which one your figure is in before you type it.
Know what to draw. Now know what you’re drawing.
Each protocol explains the compound, the research behind it and a conservative place to start.
Dev: worked examples for approval
Arithmetic illustrations only, not suggested amounts. Removed from the page before launch.
| Vial | Water | Amount | Concentration | Volume | Mark | Draws |
|---|---|---|---|---|---|---|
| 5 mg | 2 mL | 250 mcg | 2.5 mg/mL | 0.1 mL | 10 units | 20 |
| 10 mg | 2 mL | 0.5 mg | 5 mg/mL | 0.1 mL | 10 units | 20 |
| 50 mg | 3 mL | 5 mg | 16.6667 mg/mL | 0.3 mL | 0.3 mL | 10 |