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Peptide calculator: reconstitution and units

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

1. Peptide in the vial

2. Bacteriostatic water added

Quick picks are water volumes for the vial, nothing else.

3. Amount per draw

Enter the amount you want the arithmetic for. The calculator does not suggest one.

4. Syringe (U-100 insulin)
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
–
 
0102030405060708090100units

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.

Worked example

A worked example, arithmetic only

  1. Example: a 10 mg vial with 2 mL of bacteriostatic water added.
  2. Concentration: 10 mg ÷ 2 mL = 5 mg/mL, which is 5000 mcg/mL.
  3. On a U-100 syringe, 1 unit is 0.01 mL, so each unit of that solution holds 0.05 mg (50 mcg), and the full 2 mL is 200 units.
  4. Any other figure follows the same two steps: divide to get the concentration, then multiply by 100 to turn millilitres into units. The calculator does both for whatever numbers you enter.

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.

FAQ

Peptide calculator questions

What does this peptide calculator work out?

From the milligrams in a vial, the millilitres of bacteriostatic water added, an amount per draw you enter and a U-100 syringe size, it works out the concentration in mg/mL, the volume of one draw in mL, the reading in units on the syringe and the whole draws in the vial.

How is peptide concentration calculated?

Concentration in mg/mL is the vial's milligrams divided by the millilitres of water added. A 10 mg vial with 2 mL of water is 5 mg/mL. Multiply by 1000 for mcg/mL.

How many units are in 1 mL on an insulin syringe?

A U-100 insulin syringe divides 1 mL into 100 units, so one unit is 0.01 mL. Units are a volume marking, not an amount of peptide; the amount in a unit depends on the concentration.

Does the calculator suggest an amount?

No. It only divides and multiplies the numbers entered. It never suggests, pre-fills or recommends an amount per draw, a frequency or a length of use. Products are supplied for research use only.

Can I put this calculator on my own site?

Yes. Copy the embed code on this page. The calculator runs inside the frame, and the link back to this page stays visible under it.

Embed

Embed this calculator on your site

Paste this into any page. The calculator runs in the frame and the link back to this page stays visible under it.

<iframe src="https://www.primaralabs.com/embed/peptide-calculator" title="Peptide calculator" width="100%" height="900" style="border:0;max-width:720px" loading="lazy"></iframe>
<p><a href="https://www.primaralabs.com/tools/peptide-calculator">Peptide calculator by Primara Labs</a></p>

Guides

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