How do I read a reconstitution chart?

Find your vial size down the side and the amount of diluent you added across the top. The cell where they meet is how many micrograms one unit on a U-100 insulin syringe delivers. Divide your dose by that figure to get the units to draw.

Is there a standard amount of water for a 5 mg vial?

No. Any volume the vial physically holds is valid, and it changes only the syringe reading, never the dose or the number of doses. 1, 2 and 5 mL are all common because they give convenient numbers, not because any is correct.

Does this chart tell me what dose to take?

No. It converts between a vial, a diluent volume and a syringe reading. What dose is appropriate is not an arithmetic question and is not something this site answers.

Peptide Reconstitution Chart

Every cell below is generated by the same engine as the calculator, so the chart and the tool cannot disagree.

What one unit is worth

Micrograms delivered by one printed unit on a U-100 insulin syringe, for each vial and diluent pairing. This is the figure everything else follows from: divide your dose in micrograms by it to get the units to draw.

mcg per unit, U-100
Vial	1 mL	1.5 mL	2 mL	3 mL	5 mL
2 mg	20	13.3	10	6.7	4
5 mg	50	33.3	25	16.7	10
10 mg	100	66.7	50	33.3	20
15 mg	150	100	75	50	30
20 mg	200	133.3	100	66.7	40
30 mg	300	200	150	100	60

The diagonal where the numbers come out at exactly 10 is the matched-volume arrangement: as many millilitres of diluent as the vial holds milligrams. On that line the units to draw are simply the dose in micrograms divided by ten.

Units to draw, 10 mg vial in 2 mL

The most common single pairing, worked through for a range of dose sizes on a 0.5 mL (50 unit) barrel.

Dose	Volume	Units	Lands on a mark?
100 mcg	0.02 mL	2	Yes
200 mcg	0.04 mL	4	Yes
250 mcg	0.05 mL	5	Yes
300 mcg	0.06 mL	6	Yes
400 mcg	0.08 mL	8	Yes
500 mcg	0.1 mL	10	Yes
750 mcg	0.15 mL	15	Yes
1000 mcg	0.2 mL	20	Yes
1500 mcg	0.3 mL	30	Yes
2000 mcg	0.4 mL	40	Yes

Where the last column says no, the dose falls between two printed lines and has to be approximated. Changing the diluent volume moves it onto a line, which the diluent volume calculator works out directly.

What this chart is not

It is a conversion table, not a dosing table. It tells you what a vial and a volume of water make one syringe mark worth. It does not tell you what dose to take, and nothing on this site does, because that is not an arithmetic question.

The other direction, working out how long a vial lasts at a given dose, is the doses per vial calculator.

Questions

How do I read a reconstitution chart?: Find your vial size down the side and the amount of diluent you added across the top. The cell where they meet is how many micrograms one unit on a U-100 insulin syringe delivers. Divide your dose by that figure to get the units to draw.
Is there a standard amount of water for a 5 mg vial?: No. Any volume the vial physically holds is valid, and it changes only the syringe reading, never the dose or the number of doses. 1, 2 and 5 mL are all common because they give convenient numbers, not because any is correct.
Does this chart tell me what dose to take?: No. It converts between a vial, a diluent volume and a syringe reading. What dose is appropriate is not an arithmetic question and is not something this site answers.