Peptide calculator
Enter what is in the vial, how much water you added, and the dose you want. You get the exact number of clicks to dial, what each click actually delivers, and a warning if the answer falls between two clicks.
One unit is one click is 0.01ml on every pen we sell. If you have used an insulin syringe, it is the same scale.
The number printed on the vial label. Usually 5mg or 10mg.
Your choice. More water means a bigger, easier-to-dial number. Less water means fewer clicks but less room for error.
In micrograms. 1mg is 1,000mcg.
The V2 and disposable pens hold 60 units. The V1 holds 80. This only changes whether we warn you that the dose won't fit in one go.
5 clicks
Each click delivers 50mcg at 5mg per ml.
For research and laboratory use. This tool does the arithmetic only. It is not medical advice and we do not supply compounds.
How the maths works
Concentration is the vial divided by the water. A 10mg vial in 2ml of water is 5mg per ml, which is 5,000mcg per ml. One unit is a hundredth of a millilitre, so one click carries 50mcg. A 250mcg dose is therefore five clicks.
That is the whole calculation. The reason people get it wrong is not the arithmetic, it is choosing a water volume that leaves the dose sitting between two clicks. Pick the water first, check where your dose lands, and adjust before you mix rather than after.
Units, millilitres and micrograms explained goes through it slowly with worked examples.
What people ask about the maths
- How many units is 250mcg?
- It depends entirely on how much water you added. A 10mg vial mixed with 2ml of water gives 50mcg per unit, so 250mcg is 5 units. The same vial mixed with 1ml gives 100mcg per unit, so 250mcg is 2.5 units, which no pen can dial. That is why the water volume matters more than anything else.
- Is one unit the same as one click?
- Yes. On every pen we sell, one click of the dial moves one unit, which is 0.01ml. Sixty clicks is 0.6ml. This is the same scale as a standard insulin syringe.
- How much bacteriostatic water should I add?
- Enough that your usual dose lands on a whole number of clicks and sits comfortably between 10 and 40 units. Too little water and one click is a large jump. Too much and the dose will not fit in the pen. The calculator flags both cases and tells you the water volume that lands exactly on a click.
- What happens if the answer is not a whole number?
- The pen only moves in whole clicks, so you round and accept a slightly different dose. The calculator shows you exactly what you would actually deliver if you round, and suggests a water volume that removes the problem completely.
- How many doses will one vial give me?
- Divide the vial in micrograms by your dose. A 10mg vial is 10,000mcg, so at 250mcg you get 40 doses. Reconstituted peptide is limited by how long it keeps once mixed, not just by the arithmetic, so mix what you will use.