Enter how many milligrams are in the vial and how many millilitres of bacteriostatic water you added. This peptide dosage calculator returns two numbers: the concentration in mg/ml, and the exact volume that holds the amount you want to withdraw – in millilitres and microlitres, the units laboratory documentation is written in.
More calculations
This calculator converts only the numbers you enter. It gives no dosing recommendation and makes no statement about use in humans or animals. Every value stays in your browser.
What a peptide dose calculator actually works out
A lyophilised peptide arrives as a dry powder. The label states a mass – 5 mg, 10 mg, 20 mg – and nothing else. A mass cannot be drawn into a syringe; only a volume can. Converting between the two is the entire job of a peptide dosing calculator, and it needs exactly three inputs:
- Peptide in the vial. The mass printed on the label, in milligrams.
- Solvent added. How many millilitres of bacteriostatic water went into the vial.
- Amount to withdraw. The portion you are working with, in milligrams or micrograms.
The first two inputs give the concentration. The third turns that concentration into a volume. There is no fourth step, and a calculator that adds one is adding an assumption rather than arithmetic.
The whole calculation, in two lines
Concentration = peptide mass ÷ solvent volume
Withdrawal volume = desired amount ÷ concentration
mg and mcg: the mistake that costs a factor of 1000
One milligram is 1000 micrograms. Enter a figure in milligrams while thinking in micrograms and the result is a thousand times too large – enter it the other way round and it is a thousand times too small. Nothing in the arithmetic will warn you, because both numbers are perfectly valid. That is why the unit sits as a switch directly beside the input field above, not buried in a footnote. Check it before you use the result.
| Label on the vial | Same amount in micrograms |
|---|---|
| 1 mg | 1000 µg |
| 2.5 mg | 2500 µg |
| 5 mg | 5000 µg |
| 10 mg | 10 000 µg |
| 20 mg | 20 000 µg |
What the concentration number tells you
Concentration is mass divided by volume. Put 5 mg into 2 ml and you have 2.5 mg/ml. The figure is worth understanding rather than just reading off, because one shortcut makes every further conversion a mental step instead of a calculation: 1 mg/ml is exactly 1 µg/µl. At 2.5 mg/ml, one microlitre holds 2.5 micrograms. No further maths required.
The calculator also shows how many withdrawals of your chosen size the vial contains. That is the number that tells you whether a reconstitution volume is practical – a concentration so high that a withdrawal lands below the smallest graduation on your syringe is arithmetically correct and practically useless.
How much bacteriostatic water should you add?
There is no single correct answer, and any peptide bac water calculator that hands you one is inventing it. The volume is a free choice, constrained by two practical limits: the vial has to hold it, and the resulting withdrawal volume has to be large enough to measure accurately on the syringe you are using. Within those limits, more solvent means a lower concentration and a larger, easier-to-read withdrawal volume; less solvent means the opposite.
Below is the same 10 mg vial reconstituted five different ways. Nothing changes about the peptide – only the arithmetic of reading it.
| Water added to a 10 mg vial | Concentration | 1 mg sits in |
|---|---|---|
| 1 ml | 10 mg/ml | 0.1 ml (100 µl) |
| 2 ml | 5 mg/ml | 0.2 ml (200 µl) |
| 3 ml | 3.33 mg/ml | 0.3 ml (300 µl) |
| 4 ml | 2.5 mg/ml | 0.4 ml (400 µl) |
| 5 ml | 2 mg/ml | 0.5 ml (500 µl) |
Reconstitution calculator, dilution calculator, dose calculator – one piece of arithmetic
The names circulate as if they described different tools. They do not. A peptide reconstitution calculator is the first half – mass and solvent into a concentration. A peptide dilution calculator is the same division carried out again after more solvent is added. A peptide dose calculator is the second half – concentration into a volume. The calculator above does all three, which is why it has three fields rather than three pages.
No peptide calculator app to install
The tool runs in the browser, on a phone the same as on a desktop. Nothing you type is transmitted anywhere and nothing is stored – the numbers live in the page until you close it. The Copy link button writes your inputs into the address, so a particular calculation can be saved or sent on without an account, an export or a peptide calculator app.
Questions people ask about peptide calculators
How do you use a peptide calculator?
Read the mass off the vial label and type it into the first field. Type the volume of bacteriostatic water you added into the second. The concentration appears immediately. Then type the amount you want to withdraw into the third field, checking the mg/µg switch beside it, and the calculator returns the volume in millilitres and microlitres.
Peptide calculator: how much BAC water do I add?
That is your choice, not the calculator’s. The vial has to hold the volume, and the withdrawal it produces has to be readable on your syringe. Use the table above to see what different volumes do to the same 10 mg vial, then pick the one whose withdrawal volume you can measure comfortably.
How many withdrawals does one vial give?
Divide the mass in the vial by the amount per withdrawal. A 10 mg vial split into 0.5 mg portions gives twenty; into 1 mg portions, ten. The solvent volume does not change that count – it only changes how much liquid each withdrawal is. The calculator shows this figure as withdrawals per vial.
What is a peptide calculator?
A unit converter for two quantities that are easy to confuse: the mass of peptide in a vial and the volume of liquid it ends up dissolved in. It converts mass to concentration and concentration to volume. It is not a dosing tool and holds no information about any particular peptide.
How do you reconstitute a peptide?
Reconstitution means dissolving the lyophilised powder in a solvent – in laboratory practice, bacteriostatic water. The calculator covers the arithmetic of that step: what concentration a given volume of solvent produces, and what volume then contains a given mass. It makes no statement about handling, technique or storage.
Research Use Only. The products referenced on this site are supplied for laboratory research. This page is arithmetic and nothing else: it gives no dosing recommendation and makes no statement about use in humans or animals. Deutschsprachige Fassung: Peptid-Rechner