Peptide Concentration Calculator
Convert a peptide mass and solution volume into concentration, shown in mg/mL, µg/mL and µg/µL.
Calculate Peptide Concentration
Enter the total peptide mass in the solution and the total solution volume. The calculator returns the concentration in three common laboratory units at once.
Results update instantly as you type. This tool performs a mathematical calculation only — always independently verify results before using them in a laboratory procedure.
How This Calculator Works
Concentration expresses how much peptide mass is present in a given volume of solution. This calculator performs that single conversion directly: enter a mass and a volume, and it returns the concentration in the three unit pairs most commonly referenced in laboratory documentation. It does not calculate an aliquot volume — for that, use the reconstitution calculator.
Formula and Unit Definitions
Concentration = peptide mass ÷ solution volume
mg/mL (milligrams per millilitre) and µg/µL (micrograms per microlitre) are numerically identical, since both mass and volume scale by the same factor of 1,000 between units. µg/mL (micrograms per millilitre) is 1,000 times the mg/mL value. All three are calculated from the same input pair and standardized internally before conversion.
Worked Laboratory Example
Suppose a solution contains 5 mg of peptide in a total volume of 2 mL.
Concentration = 5 mg ÷ 2 mL = 2.5 mg/mL
Equivalent to 2,500 µg/mL and 2.5 µg/µL
Accuracy and Limitations
- Results are only as accurate as the mass and volume values supplied.
- This calculator assumes the peptide is fully and evenly dissolved throughout the stated volume.
- It does not account for peptide purity, degradation, or solvent compatibility.
See the full calculation methodology for rounding rules and validation logic.
Frequently Asked Questions
What is the difference between this calculator and the reconstitution calculator?
This calculator only converts a mass and volume into a concentration. The reconstitution calculator does the same conversion and then also calculates the aliquot volume needed for a target experimental quantity.
Why does the calculator show three different concentration units?
Different protocols and documentation reference concentration in mg/mL, µg/mL or µg/µL. Showing all three avoids a separate manual conversion step.
Is 1 mg/mL the same as 1 µg/µL?
Yes. Because both mass and volume scale by the same factor of 1,000 between mg/µg and mL/µL, 1 mg/mL and 1 µg/µL are numerically identical concentrations.
Can this calculator be used for human or animal dosing?
No. This calculator is not designed for, and must not be used for, human or animal dosing. It is a mathematical tool intended for laboratory research only.