Calculator

Semaglutide dose-to-units calculator

Updated by the GLP Ladder Editorial Team. Editorial policy.

Short answer

Units = dose mg ÷ concentration (mg/mL) × 100 on a U-100 syringe, where concentration = vial mg ÷ water mL. Example: a 5 mg vial in 2 mL is 2.5 mg/mL, so 0.5 mg is 0.2 mL, or 20 units. Results round to 0.5 U and show the raw value. Arithmetic as of Oct 19, 2026; not dosing advice.

Units on U-100
20 U (raw 20)
Volume
0.2 mL
Concentration
2.5 mg/mL
Draws per vial
10
Vial of 5 mg in 2 mL (2.5 mg/mL, 1 unit = 0.025 mg). Syringe drawn to 20 units of 100; nearest printed mark 20 units.123mL5 mg+ 2 mL water= 2.5 mg/mL10 draws0010200.53040150601.570802901002.5Umg812162024283220
Vial of 5 mg in 2 mL (2.5 mg/mL, 1 unit = 0.025 mg). Syringe drawn to 20 units of 100; nearest printed mark 20 units.123mL5 mg+ 2 mL water= 2.5 mg/mL10 draws0010200.53040150601.570802901002.5Umg812162024283220

Lands exactly on a printed mark: 20 U.

1 unit = 0.025 mg · 10 units = 0.25 mg at 2.5 mg/mL.

Drag the plunger, or focus the diagram and use the arrow keys, to set the amount by syringe mark.

Water volumes that put 0.5 mg exactly on a printed mark of this syringe:

Syringe filled to 20 of 100 units 0102030405060708090100 20 U
U-100 scale: 100 units = 1 mL, so 1 unit = 0.01 mL. Units round to the nearest 0.5 U.

5 mg ÷ 2 mL = 2.5 mg/mL. 0.5 mg ÷ 2.5 mg/mL = 0.2 mL × 100 = 20 U.

Math, parameters and sources: model card.

From vial to syringe: the default example (5 mg vial, 2 mL water, 0.5 mg) in three steps

  1. Vial and water

    5 mg + 2 mL

    The mg in the vial never changes; water only sets how spread out it is.

  2. Concentration

    5 ÷ 2 = 2.5 mg/mL

    Milligrams in every milliliter of solution.

  3. Units on a U-100 syringe

    0.5 mg ÷ 2.5 = 0.2 mL = 20 U

    100 units = 1 mL, so units = mL × 100 (rounded to 0.5 U).

Lookup matrix

Pre-calculated U-100 readings for common vial sizes and water volumes. Every cell uses the same formula as the calculator. Brand Wegovy and Ozempic products are ready-to-use solutions and are not reconstituted; these tables are arithmetic for lyophilized vials.

5 mg vial: U-100 units to draw for each dose (1 mL = 5 mg/mL; 2 mL = 2.5 mg/mL; 3 mL = 1.667 mg/mL)
Dose1 mL water5 mg/mL2 mL water2.5 mg/mL3 mL water1.667 mg/mL
0.25 mg 5 U10 U15 U
0.5 mg 10 U20 U30 U
1 mg 20 U40 U60 U
2 mg 40 U80 U—
2.5 mg 50 U100 U—
4 mg 80 U——
5 mg 100 U——
6 mg ———
8 mg ———
9 mg ———
10 mg ———
12 mg ———
10 mg vial: U-100 units to draw for each dose (1 mL = 10 mg/mL; 2 mL = 5 mg/mL; 3 mL = 3.333 mg/mL)
Dose1 mL water10 mg/mL2 mL water5 mg/mL3 mL water3.333 mg/mL
0.25 mg 2.5 U5 U7.5 U
0.5 mg 5 U10 U15 U
1 mg 10 U20 U30 U
2 mg 20 U40 U60 U
2.5 mg 25 U50 U75 U
4 mg 40 U80 U—
5 mg 50 U100 U—
6 mg 60 U——
8 mg 80 U——
9 mg 90 U——
10 mg 100 U——
12 mg ———
15 mg vial: U-100 units to draw for each dose (1 mL = 15 mg/mL; 2 mL = 7.5 mg/mL; 3 mL = 5 mg/mL)
Dose1 mL water15 mg/mL2 mL water7.5 mg/mL3 mL water5 mg/mL
0.25 mg 1.5 U (raw 1.67)3.5 U (raw 3.33)5 U
0.5 mg 3.5 U (raw 3.33)6.5 U (raw 6.67)10 U
1 mg 6.5 U (raw 6.67)13.5 U (raw 13.33)20 U
2 mg 13.5 U (raw 13.33)26.5 U (raw 26.67)40 U
2.5 mg 16.5 U (raw 16.67)33.5 U (raw 33.33)50 U
4 mg 26.5 U (raw 26.67)53.5 U (raw 53.33)80 U
5 mg 33.5 U (raw 33.33)66.5 U (raw 66.67)100 U
6 mg 40 U80 U—
8 mg 53.5 U (raw 53.33)——
9 mg 60 U——
10 mg 66.5 U (raw 66.67)——
12 mg 80 U——
20 mg vial: U-100 units to draw for each dose (1 mL = 20 mg/mL; 2 mL = 10 mg/mL; 3 mL = 6.667 mg/mL)
Dose1 mL water20 mg/mL2 mL water10 mg/mL3 mL water6.667 mg/mL
0.25 mg 1.5 U (raw 1.25)2.5 U4 U (raw 3.75)
0.5 mg 2.5 U5 U7.5 U
1 mg 5 U10 U15 U
2 mg 10 U20 U30 U
2.5 mg 12.5 U25 U37.5 U
4 mg 20 U40 U60 U
5 mg 25 U50 U75 U
6 mg 30 U60 U90 U
8 mg 40 U80 U—
9 mg 45 U90 U—
10 mg 50 U100 U—
12 mg 60 U——
30 mg vial: U-100 units to draw for each dose (1 mL = 30 mg/mL; 2 mL = 15 mg/mL; 3 mL = 10 mg/mL)
Dose1 mL water30 mg/mL2 mL water15 mg/mL3 mL water10 mg/mL
0.25 mg 1 U (raw 0.83)1.5 U (raw 1.67)2.5 U
0.5 mg 1.5 U (raw 1.67)3.5 U (raw 3.33)5 U
1 mg 3.5 U (raw 3.33)6.5 U (raw 6.67)10 U
2 mg 6.5 U (raw 6.67)13.5 U (raw 13.33)20 U
2.5 mg 8.5 U (raw 8.33)16.5 U (raw 16.67)25 U
4 mg 13.5 U (raw 13.33)26.5 U (raw 26.67)40 U
5 mg 16.5 U (raw 16.67)33.5 U (raw 33.33)50 U
6 mg 20 U40 U60 U
8 mg 26.5 U (raw 26.67)53.5 U (raw 53.33)80 U
9 mg 30 U60 U90 U
10 mg 33.5 U (raw 33.33)66.5 U (raw 66.67)100 U
12 mg 40 U80 U—
40 mg vial: U-100 units to draw for each dose (1 mL = 40 mg/mL; 2 mL = 20 mg/mL; 3 mL = 13.333 mg/mL)
Dose1 mL water40 mg/mL2 mL water20 mg/mL3 mL water13.333 mg/mL
0.25 mg 0.5 U (raw 0.63)1.5 U (raw 1.25)2 U (raw 1.88)
0.5 mg 1.5 U (raw 1.25)2.5 U4 U (raw 3.75)
1 mg 2.5 U5 U7.5 U
2 mg 5 U10 U15 U
2.5 mg 6.5 U (raw 6.25)12.5 U19 U (raw 18.75)
4 mg 10 U20 U30 U
5 mg 12.5 U25 U37.5 U
6 mg 15 U30 U45 U
8 mg 20 U40 U60 U
9 mg 22.5 U45 U67.5 U
10 mg 25 U50 U75 U
12 mg 30 U60 U90 U
60 mg vial: U-100 units to draw for each dose (1 mL = 60 mg/mL; 2 mL = 30 mg/mL; 3 mL = 20 mg/mL)
Dose1 mL water60 mg/mL2 mL water30 mg/mL3 mL water20 mg/mL
0.25 mg 0.5 U (raw 0.42)1 U (raw 0.83)1.5 U (raw 1.25)
0.5 mg 1 U (raw 0.83)1.5 U (raw 1.67)2.5 U
1 mg 1.5 U (raw 1.67)3.5 U (raw 3.33)5 U
2 mg 3.5 U (raw 3.33)6.5 U (raw 6.67)10 U
2.5 mg 4 U (raw 4.17)8.5 U (raw 8.33)12.5 U
4 mg 6.5 U (raw 6.67)13.5 U (raw 13.33)20 U
5 mg 8.5 U (raw 8.33)16.5 U (raw 16.67)25 U
6 mg 10 U20 U30 U
8 mg 13.5 U (raw 13.33)26.5 U (raw 26.67)40 U
9 mg 15 U30 U45 U
10 mg 16.5 U (raw 16.67)33.5 U (raw 33.33)50 U
12 mg 20 U40 U60 U

Units = dose mg ÷ (vial mg ÷ water mL) × 100, rounded to the nearest 0.5 U; the raw value is shown in brackets when rounding changed it. A dash means the draw would exceed a 100-unit syringe or the vial. Arithmetic only; not dosing advice.

Rounding, syringe size and dead space

Results round to the nearest 0.5 unit because U-100 syringes are marked in 1-unit (30 and 50 U) or 2-unit (100 U) steps; the raw value is always shown next to the rounded one. The calculator warns when a draw exceeds the chosen syringe or falls under 2 units, where a half-unit reading error is 25% or more of the amount. Dead space (liquid held in the hub and needle) does not change the units for one draw, but it lowers how many draws a vial yields.

Frequently asked questions

How many units is 1 mg of semaglutide?

It depends on the concentration. At 2.5 mg/mL (5 mg in 2 mL), 1 mg is 0.4 mL = 40 units; at 5 mg/mL it is 20 units. Units = mg ÷ (mg/mL) × 100.

What does U-100 mean?

A U-100 insulin syringe is marked so that 100 units equal 1 mL. One unit is therefore 0.01 mL. The unit marks measure volume only; how many mg a unit holds depends entirely on the concentration of the solution.

Why does the calculator warn under 2 units?

Small volumes are hard to read on a syringe scale. Below about 2 units, a half-unit reading error is 25% or more of the dose, so the tool flags it. A more dilute concentration gives a larger, easier-to-read volume for the same mg.

What is dead space?

Dead space is liquid left in the syringe hub and needle after a draw. It does not change the units for a dose but reduces how many draws a vial yields. Enter it in units to see the adjusted doses per vial.

Is semaglutide FDA approved?

Yes. FDA approved as Ozempic (type 2 diabetes) and Wegovy (weight management, cardiovascular risk reduction). Numbers on this page quote the FDA prescribing information; your prescriber sets your dose.

Sources

  1. WEGOVY (semaglutide) injection, for subcutaneous use; WEGOVY (semaglutide) tablets, for oral use - Full Prescribing Information (SPL, Revised 6/2026). Novo Nordisk / National Library of Medicine DailyMed, Jun 18, 2026. Accessed Oct 19, 2026.
  2. OZEMPIC (semaglutide) injection, for subcutaneous use - Full Prescribing Information (SPL). Novo Nordisk / National Library of Medicine DailyMed, Jun 1, 2026. Accessed Oct 19, 2026.

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