Molecular weight unit equivalence
Protein molecular weight is commonly written in daltons or kilodaltons.
For biochemical calculations, daltons are numerically equivalent to g/mol, while 1 kDa equals 1000 Da.
Calculator
Molecular Weight / kDa Calculator
Result
Molecular weight: 50 kDa
Equivalent: 50000 Da
Equivalent: 50000 g/mol
Numerically, Da and g/mol are equivalent for molecular weight; 1 kDa = 1000 Da.
Practical use
Use this calculator as a planning aid for molecular biology, biochemistry, protein science, cloning, PCR, and routine bench preparation workflows.
Results should be interpreted alongside your protocol, instrument settings, reagent quality, and laboratory safety requirements.
How to cite this tool
Citation
If this calculator supports your research, you may cite it as a web-based tool.
Abdulfattah, M. A. Molecular Weight / kDa Calculator. Mustafa A Abdulfattah Academic Website. Available at: https://www.mustafaabdulfattah.com/tools/protein-molecular-weight-calculator. Accessed today.
BibTeX
@misc{abdulfattah_protein_molecular_weight_calculator_2026,
author = {Abdulfattah, Mustafa A.},
title = {Molecular Weight / kDa Calculator},
year = {2026},
url = {https://www.mustafaabdulfattah.com/tools/protein-molecular-weight-calculator},
note = {Accessed today}
}FAQ
Molecular Weight / kDa Calculator questions
Is Da the same as g/mol?↑
For molecular weight calculations, the numerical value in Da corresponds to the numerical value in g/mol.
How many Da are in 1 kDa?↑
One kDa equals 1000 Da.
Why do protein calculations use kDa?↑
kDa is convenient because many proteins have molecular weights in the tens or hundreds of thousands of daltons.
Can I use this for concentration conversion?↑
Use this page to normalize molecular weight units, then use the protein concentration unit converter for concentration conversion.