Tools / Calculations
Peptide calculator.
Calculate the concentration of a solution, the volume for a selected amount of peptide and the amount in a selected volume. Results update live and run locally in your browser.
At a glance
- — concentration in mg/mL and µg/mL
- — conversions mg ↔ µg and mL ↔ µL
- — optional U-100 scale mark
- — no storage of entries
Formulas
What is calculated.
All values are converted to mg and mL before calculation. Results are shown to six significant figures, while the calculation keeps full precision for intermediate values.
Concentration
c = m / V
c is the concentration in mg/mL, m is the amount of peptide in mg, and V is the final volume of the solution in mL.
Amount → volume
V(selected) = m(selected) / c
Divide the selected amount by the concentration of the solution. The result is the volume in mL or µL.
Volume → amount
m(selected) = c × V(selected)
Multiply the selected volume by the concentration. The result is the amount in mg or µg.
Conversions and mark
1 mg = 1000 µg · 1 mL = 1000 µL
The U-100 scale mark is the volume expressed in hundredths of a millilitre. It is not a dose and does not describe the amount of peptide.
Worked example
The vial contains 5 mg of peptide. We add 2 mL of solvent, so the final volume of the solution is 2 mL.
- Concentration: c = 5 mg ÷ 2 mL = 2.5 mg/mL or 2500 µg/mL.
- For a selected amount of 250 µg, first convert: 250 µg = 0.25 mg. Volume: V = 0.25 mg ÷ 2.5 mg/mL = 0.1 mL or 100 µL.
- U-100 scale mark: 0.1 mL × 100 = 10. On a 1 mL scale, this is one tenth of the 0–100 range.
For 62.5 µg the result is 0.025 mL or 25 µL, and the mark is 2.5. For 1 mg the result is 0.4 mL or 400 µL; on a 0.3 mL scale (0–30) the mark 40 exceeds the scale, so a warning is shown while the result remains visible.
How to read the result
| Term | Meaning |
|---|---|
| Concentration | The amount of peptide per unit volume of solution, regardless of the selected amount or volume. |
| mg/mL and µg/mL | The same concentration in two units. 1 mg/mL equals 1000 µg/mL. |
| mL and µL | The volume of solution. 1 mL equals 1000 µL; 0.1 mL is 100 µL. |
| U-100 mark | Volume in mL multiplied by 100. A mark of 10 means 0.1 mL, not 10 units of peptide. |
Calculator limitations
- Handles one vial or one peptide at a time; it is not intended for mixtures.
- Assumes that all peptide is dissolved and evenly distributed.
- Uses the entered amount and does not account for purity, water content or salt.
- The entered volume is the final volume of the solution, not the amount of solvent added.
- The U-100 mark describes volume and is not a dosing recommendation.
- The calculation is informational and does not replace a laboratory protocol.
To convert between mass, moles and molar concentration, use the laboratory converter . For preparing a solution, read storage and reconstitution of peptides , and for understanding purity data, how to read a certificate of analysis .