Bioinformatics toolProtein analysisBrowser-side

Protein Concentration Calculator

Convert protein concentration between mg/mL and molarity using molecular weight, then estimate nmol for your sample volume.

Open calculatorBioinformatics hub
mg/mL, g/L, and µg/mLµM, nM, and mMnmol by sample volume
Quick conversion rule
For protein concentration in mg/mL, use the molecular weight in kDa to move between mass and molar units.

µM = (mg/mL × 1000) / kDa

mg/mL = (µM × kDa) / 1000

1 µM in 1 mL = 1 nmol

Calculator inputs
Enter one concentration value, the protein molecular weight, and the sample volume.

Assumption

This calculator treats 1 Da as 1 g/mol and uses the molecular weight you enter. It is meant for quick concentration conversion, not extinction-coefficient-based quantification.

Calculated results
Read the equivalent concentration, molarity, and total amount for your sample.

Mass concentration

1.000mg/mL
1.000g/L
1,000µg/mL

Molar concentration

20.00µM
20,000nM
0.0200mM

Sample totals

20.00nmol
1.000mg

Short formula view

Mass input is converted to molarity, then multiplied by sample volume to estimate total nmol.

50.00 kDa protein: 1.000 mg/mL = 20.00 µM; 20.00 nmol in 1.000 mL.

Live resultMass to molar

For a protein concentration workflow, the key step is converting the mass-based input into molarity using the molecular weight. That is why the calculator asks for kDa.

Why this calculator is useful

Protein concentration shows up in prep, QC, chromatography, assay design, and notebook-based analysis.

Two-way conversion
Convert from protein mass concentration to molarity, or enter a molar value and recover the equivalent mass concentration.
Sample-volume aware
Estimate total nmol and total mg in the sample volume you provide, which is useful for prep and downstream experiments.
Browser-side calculation
Everything runs locally in your browser. No upload, no login, and no dependency on a server-side calculator.
Unit reference
These are the conventions the calculator uses.

mg/mL

Numerically equal to g/L for aqueous protein solutions.

µg/mL

1,000 µg/mL = 1 mg/mL.

µM

1 µM in 1 mL equals 1 nmol.

kDa

1 kDa = 1,000 g/mol, which makes the conversion straightforward.

Example conversions
A few common protein-analysis scenarios to sanity-check your inputs.

Albumin-like protein

66.5 kDa at 1 mg/mL is about 15.0 µM, or 15.0 nmol in 1 mL.

Medium-size enzyme

50 kDa at 0.5 mg/mL is about 10.0 µM, or 10.0 nmol in 1 mL.

Molar input

100 kDa at 2 µM is equivalent to 0.20 mg/mL.

Frequently asked questions

A few quick answers before you use the calculator in a lab or notebook workflow.

It converts protein concentration between mass units and molarity using the molecular weight you enter. It also estimates total nmol in the sample volume.

Related tools
This calculator works best as one step inside a broader sequence and protein-analysis cluster.
DNA Concentration Calculator

Keep DNA and protein prep calculations close together.

GC Content Calculator

Return to sequence-level QC before deeper analysis.

Reverse Complement

Prep the upstream sequence if your protein work starts from DNA.

Restriction Site Finder

Check cloning motifs before the workflow moves protein-side.

Runcell workflow handoffProtein analysis

Use this calculation before notebook-based protein analysis

Convert the numbers here, then move into Runcell for downstream interpretation, comparison, and notebook-based analysis.

Open notebook workflowsOpen bioinformatics hub