Calculate DNA concentration from absorbance

Calculate DNA concentration from A260

Calculate plasmid DNA concentration from a260 values

Online tools to calculate DNA properties, DNA solution concentration, dilution and absorbance.

Online DNA calculator of DNA solution and DNA dilution

Online DNA calculations

DNA MW calculation

DNA molecular weight calculation

DNA molarity calculation

DNA base pair molarity calculation

DNA concentration calculation

Determine DNA concentration from absorbance

DNA MW calculator

dna mw conversion

Calculate DNA MW

Calculate DNA molecular weight

DNA molarity calculator, oligo concentration

DNA base pair molarity calculator

DNA concentration calculator

calculating plasmid concentration from a260

DNA GC content calculator

dna to rna convertor, dna to rna sequence converter

dna to mrna converter

number of bases in dna

Number of DNA molecules calculation

OD260 calculator, absorbance 260, absorbance to molarity, dna concentration determination

bp corresponds to what molecular weight

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DNA Calculator

Useful links Send feedback! User guide

Molbiotools is a collection of free online apps:

DNA Sequence Tools
Text and Data Tools

Sequence input and settings

Open a sequence file (txt, fasta or GenBank format) or paste a sequence in the area bellow.

Set the nucleic acid parameters:

single strand
double strand
5' hydroxyl
5' phosphate
5' triphosphate

Calculated properties


GC content:

Molecular weight:

Molarity of 1 μg/μl solution:

Number of molecules in 1 μg:

Approx. 260 nm extinction coefficient:

A260 of 1 μg/μl solution after 100-fold dilution:

In the following boxes, always fill all but one field and click 'Calculate'. Don't use commas to separate thousands.


Absorbance and concentration

Nucleic acid:
260 nm absorbance:(in a 1 cm cuvette)
Dilution factor:
Original concentration: μg/μl
For the calculation use:
empirical rules
predicted extinction coefficient

Molarity, mass and volume


Base-pair molarity of dsDNA solutions

Mass (amount of dsDNA):μg
Concentration of base pairs:mM

DISCLAIMER: This free software comes without any warranty. The author of the software bears no responsibility for any loss or damage that may arise from its use for any purpose.