Protein Molarity Calculator
This protein molarity calculator converts protein concentration (mg/mL or µg/mL) to molar concentration (µM, nM). Enter the protein concentration and molecular weight in kDa to get instant results for binding assays, enzyme kinetics, and structural biology experiments.
Protein Molarity Calculator
Protein Concentration → Molarity
M = (mg/mL) / (kDa × 1000) What is Protein Molarity?
Protein molarity is the molar concentration of a protein in solution. Since proteins have large molecular weights (typically 10–200 kDa), their molar concentrations are usually in the micromolar (µM) or nanomolar (nM) range.
Protein molecular weight is measured in kilodaltons (kDa). 1 kDa = 1,000 g/mol. For example, BSA (bovine serum albumin) is 66.5 kDa = 66,500 g/mol.
Knowing protein molarity is essential for stoichiometric calculations in binding assays (Kd determination), enzyme kinetics (Km and Vmax), crystallography, and biophysical measurements (ITC, SPR).
Protein Molarity Formula
The formula for calculating molarity from protein concentration:
To use this formula, you need protein concentration and molecular weight. The calculator handles all unit conversions automatically.
Enter your values below to see the protein molarity formula in action.
Where mass is in grams (g), volume is in liters (L), and molar mass is in g/mol.
How to Calculate Protein Molarity
Follow these steps to calculate molarity from protein concentration:
- Identify the protein concentration of your solute and gather all known values.
- Find the molar mass of the substance from the periodic table or a chemical database.
- Enter your protein concentration value and select the appropriate unit from the dropdown.
- Enter the volume of the solution in liters (L) or select another volume unit.
- Click Calculate to get the molarity result instantly.
- Verify the result using the step-by-step breakdown provided by the calculator.
Protein Molarity Calculator Examples
The examples below show how to use the protein molarity calculator in practice.
Example 1: What is the molarity of 1 mg/mL BSA? BSA MW ≈ 66.5 kDa = 66,500 g/mol. M = 1 / 66500 = 1.50 × 10⁻⁵ M = 15.0 µM.
Example 2: Using the formula: molarity = moles ÷ volume, compute the result and verify with the calculator above.
Example 3: Enter your own values into the calculator to see personalized step-by-step results.
Molarity Calculator Tools
Explore our collection of 20 specialized molarity calculators. Each tool is designed for a specific type of calculation with its own unique input fields and formulas.
FAQs
How do you calculate protein molarity?
M = concentration (mg/mL) ÷ molecular weight (kDa). Since mg/mL = g/L and kDa = g/mmol, M = (g/L) / (g/mol × 1000).
What is the molarity of 1 mg/mL BSA?
BSA MW ≈ 66.5 kDa = 66,500 g/mol. M = 1 / 66500 = 1.50 × 10⁻⁵ M = 15.0 µM.
Why is protein molarity important?
Protein molarity is essential for stoichiometric calculations in binding assays, enzyme kinetics, and structural biology experiments.
What units does the Protein Molarity Calculator support?
The protein molarity calculator supports mass units (g, mg, µg, kg), volume units (L, mL, µL, gal), molar mass (g/mol, kg/mol), and molarity units (M, mM, µM, nM, pM, fM, aM).
Is the Protein Molarity Calculator free to use?
Yes. The protein molarity calculator is 100% free, requires no sign-up, and works on all devices. All calculations are performed instantly in your browser.