mg to units converter
Convert milligrams to units on a U-100 insulin syringe and back, from a concentration you enter, and units to millilitres. It works for any liquid because it knows nothing about what is in the syringe: every field starts empty and every number in the answer is one you supplied.
This is a calculator only. It converts units of measurement and does not suggest any amount, schedule or substance. Dosing decisions belong with a licensed clinician.
Converter
mg and units
Enter a concentration and a figure to convert. Milligrams and units cannot be converted without the concentration.
Units and mL
No concentration needed: on a U-100 syringe, 100 units is 1 mL whatever the syringe holds.
From a vial: concentration first
If you know the vial strength and the volume of liquid added rather than the concentration, this works the concentration out, then converts.
Enter the vial strength and the volume of liquid added to see the concentration.
For the full reconstitution walkthrough, syringe sizes and the reconstitution chart, use the peptide reconstitution calculator.
U-100 syringe units to mL
On a U-100 syringe, 100 units is exactly 1 mL, so each unit is 0.01 mL. This holds for every U-100 barrel and every liquid, which is why the table needs no concentration.
| Syringe reading | Volume in the syringe |
|---|---|
| Draw to 1 units | 0.01 mL |
| Draw to 2 units | 0.02 mL |
| Draw to 5 units | 0.05 mL |
| Draw to 10 units | 0.10 mL |
| Draw to 15 units | 0.15 mL |
| Draw to 20 units | 0.20 mL |
| Draw to 25 units | 0.25 mL |
| Draw to 30 units | 0.30 mL |
| Draw to 40 units | 0.40 mL |
| Draw to 50 units | 0.50 mL |
| Draw to 60 units | 0.60 mL |
| Draw to 70 units | 0.70 mL |
| Draw to 80 units | 0.80 mL |
| Draw to 90 units | 0.90 mL |
| Draw to 100 units | 1.00 mL |
How the conversion works
Milligrams and units measure different things. A milligram is an amount of a substance; a unit is a distance on the syringe barrel, which is a volume. The concentration, in mg per mL, is what links the two, and it is set by whatever is in the vial, not by the syringe. That is why the converter asks for it before it will turn one into the other.
The working, as the converter applies it:
- mL = units ÷ 100
- units = mg ÷ concentration (mg/mL) × 100
- mg = units ÷ 100 × concentration (mg/mL)
- concentration (mg/mL) = vial strength (mg) ÷ liquid added (mL)
Results are shown to two decimal places in units and three in millilitres, and are never rounded to a whole unit, because a half unit is a real reading on a fine barrel. If you have an amount in micrograms, divide by 1,000 to get milligrams first.
Frequently asked questions
How many mL is 30 units?
0.30 mL. On a U-100 syringe every unit is one hundredth of a millilitre, so 30 units is 0.30 mL whatever is in the syringe and whatever size the barrel is. The same rule gives 10 units as 0.10 mL and 50 units as 0.50 mL.
How do I convert mg to units?
Divide the amount in mg by the concentration in mg/mL to get millilitres, then multiply by 100. Milligrams measure how much of a substance there is and units measure volume on the syringe, so there is no fixed number of units in a milligram: the same amount can be a few units or a whole barrel depending on how concentrated the liquid is.
How do I convert units to mg?
Divide the units by 100 to get millilitres, then multiply by the concentration in mg/mL. Without the concentration the question has no answer, which is why the converter asks for it first.
What does U-100 mean?
It describes the graduation scale of the syringe: 100 units on the barrel is exactly 1 mL. It is a property of the syringe, not of what is in it, and it is the same on a 0.3 mL, 0.5 mL and 1 mL barrel.
Does syringe size change the conversion?
No. A 0.3 mL syringe holds 30 units, a 0.5 mL syringe holds 50 units and a 1 mL syringe holds 100 units, but a unit is one hundredth of a millilitre on all three. Barrel size decides how much fits and how finely the scale can be read, never what a unit is worth.
Who decides the amount?
A licensed clinician. This page converts between units of measurement and supplies no figure of its own: every number in the result is one you entered.
Talk it through with a clinician
A converter checks arithmetic. Whether an amount is right for you is a question for a licensed clinician, and PCF lists clinics you can contact directly.
Find a clinic near youBefore you use this
This tool performs arithmetic only. It does not recommend a dose, a frequency, a duration or a supplier. Many peptides discussed online are not approved by the FDA for the uses people describe. Compounded medicines are supplied on prescription and should be prepared exactly as your pharmacy instructs. Talk to a prescriber or pharmacist before preparing or administering anything.