GLP-1 dose calculator: mg to units.
Start with the label on your vial. Enter how much medication it holds and how much liquid, then the dose your prescriber gave you. The calculator turns it into mL and the matching mark on a U-100 syringe.
For education and arithmetic only. Not medical advice, and not a dosing, mixing or treatment recommendation. Confirm your medication, dose and measurements with your prescriber or pharmacist.
How it works
Concentration
mg in the vial ÷ mL of liquid = mg per mL.
Volume
Your dose in mg ÷ concentration = mL to draw.
Syringe units
On a U-100 syringe, 1 mL = 100 units, so mL × 100 = units.
Doses per vial
mg in the vial ÷ your dose, rounded down to whole doses.
Questions
Does this tell me what dose to take?
No. You enter the dose your prescriber gave you. The calculator only converts it between mg, mL and syringe units.
What is a U-100 syringe?
A syringe scale with 100 units per mL, so each unit is 0.01 mL. The units measure volume, not medication: how much medication a unit holds depends on your vial’s concentration.
Why does it ask for the syringe size?
A calculated volume can be more than the syringe holds. The calculator warns you when it does instead of showing a number you cannot draw.
Is this for compounded medication only?
It is most useful for compounded vials, which are labelled in mg and mL. Branded pens such as Ozempic or Zepbound are set by dose and do not need this conversion.
Why do the FDA and pharmacists warn about this?
Mixing up mg, mL and syringe units has led to dosing errors with compounded semaglutide. If any number here differs from what your pharmacy told you, follow your pharmacy and ask them.
How many units is 0.25 mg of semaglutide?
It depends entirely on your vial’s concentration. At 2.5 mg/mL it is 0.1 mL, which is 10 units on a U-100 syringe; at 5 mg/mL it is 5 units. Enter your own vial to see yours.
How do I convert mg to mcg?
Multiply by 1,000. 0.5 mg is 500 mcg.
How many units are in 1 mL?
On a U-100 syringe, 100 units. Each unit is 0.01 mL.
Does the calculator send my numbers anywhere?
No. It runs in your browser; nothing you type leaves the page.
Can Steady remember my dose and remind me?
Yes. Steady keeps the dose from your prescription and reminds you on dose day with how much to take.