Peptide reconstitution calculator

The Primara Labs peptide reconstitution calculator turns four numbers you enter (the milligrams in a vial, the millilitres of bacteriostatic water added, an amount per draw and the U-100 syringe size) into the concentration, the volume of one draw, the reading on the syringe and the whole draws in the vial. It is arithmetic only: it does not suggest or recommend any amount, and nothing entered leaves the browser.

Updated 24 September 2026

Calculator

Enter the numbers

Concentration: –; Needs vial and water
Volume per draw: –; Needs an amount per draw
Units on the 1 mL syringe: –; U-100: 100 units = 1 mL
Draws per vial: –

Tick model: the 1 mL syringe is drawn with a mark every 2 units, the usual printing (0.3 mL and 0.5 mL U-100 syringes are usually marked every 1 unit, the 1 mL every 2 units). Check the barrel you hold.

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Before you rely on a number

Products are supplied for laboratory research use only.
This page is not medical advice.
The calculator does not recommend amounts. It only divides and multiplies the numbers entered.
Verify the arithmetic yourself with the formulas below before relying on any result.

Formulas

How each number is worked out

Concentration: concentration (mg/mL) = vial mg ÷ water mL. 5 mg in 2 mL is 2.5 mg/mL; 15 mg in 3 mL is 5 mg/mL. Multiply by 1000 for mcg/mL.
Volume per draw: volume (mL) = amount per draw in mg ÷ concentration in mg/mL. An amount entered in mcg is divided by 1000 first.
Units on a U-100 syringe: units = volume in mL × 100, because a U-100 syringe divides 1 mL into 100 units. One unit is 0.01 mL.
Draws per vial: draws = vial mg ÷ amount per draw in mg, rounded down to whole draws.
Syringe fills: fills = units ÷ syringe capacity in units, rounded up. More than one fill means the draw does not fit the syringe chosen.
Nearest readable mark: the units rounded to the nearest printed mark, with the difference shown in units, mL, mcg and percent.

Tick model

How the syringe marks are read

All three syringes are U-100 insulin syringes: 100 units make 1 mL. The calculator assumes the usual printing: the 0.3 mL (30 units) is marked every 1 unit, the 0.5 mL (50 units) is marked every 1 unit, the 1 mL (100 units) is marked every 2 units. Some brands print half-unit marks on small barrels; check the syringe you hold.

When a result falls between two marks, the calculator shows the nearest readable mark and how far that mark is from the computed volume. Changing the water volume changes the concentration, and can move a result onto a mark.

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