The Peptide Calculator

Peptide calculator

Enter the vial strength, the diluent added and the amount to measure. Answers update as you type.

Educational arithmetic only. Not medical advice and not a dosing protocol.

No default: the same volume reads differently on each.
Measured the finished volume? Add it for an exact concentration
The volume in the vial after mixing. With it, the concentration is a measurement rather than an upper bound.

Fill in the fields above to see the answer.

Read this with the answer

This is educational arithmetic on figures entered by the reader. It is not medical advice, not a dosing protocol, and not a recommendation that anything be prepared, obtained or administered.

Nothing here states what quantity is appropriate for anyone, and there is no function in it that produces an amount to administer. A question about anyone’s health belongs with a licensed clinician who can examine the person asking.

Most compounds named here are research chemicals that are not approved by the FDA for human use. An exact calculation is not an accurate measurement: what is actually in a syringe depends on the preparation and the device, neither of which this page can see.

No qualified clinical reviewer is recorded against this site, and no credential is claimed anywhere on it. Full disclaimer.

Show the working
  1. Concentration is the vial mass divided by the volume of the finished solution: c = m / V.
  2. The finished volume is the diluent plus whatever space the solid itself takes up. With that displacement unknown, V ≥ diluent, so m / diluent is the highest the concentration can be, and it is labelled an upper bound rather than printed as a fact.
  3. The volume holding a given amount is that amount divided by the concentration: V = dose / c.
  4. Syringe units are the volume multiplied by the barrel calibration: units = V × units-per-mL. U-100 is 100 per mL, U-50 is 50, U-40 is 40.

Three things this does differently

The concentration is an upper bound when that is all the inputs support

A dissolved solid occupies volume, so the finished solution is larger than the diluent added and the true concentration is lower than mass divided by diluent. Most calculators print that figure as fact. This one prints it as the ceiling it is, and says so next to the number. Entering a measured final volume removes the uncertainty.

The syringe scale is never assumed

0.2 mL is 20 units on a U-100 barrel, 10 on a U-50 and 8 on a U-40. A tool that quietly assumes U-100 is out by a factor of two or two and a half for anyone holding something else, and the answer would look no different. So the scale is a required choice with no default.

It says when a figure cannot be read on the barrel

7.142857 units is arithmetically correct and unreadable on a barrel marked every unit. The answer names the nearest printed mark, and flags a draw within two graduations of zero where the reading error is a large share of the amount measured.

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