🧬 DNA Concentration Calculator
Convert a spectrophotometer A260 absorbance reading into DNA or RNA concentration and total sample yield.
What this calculator does
The DNA Concentration Calculator converts a spectrophotometer reading (absorbance at 260 nm, or A260) into a nucleic acid concentration in nanograms per microliter, then estimates the total yield in your sample tube.
The formula it uses
Nucleic acid concentration is calculated as Concentration (ng/µL) = A260 × Dilution Factor × Conversion Factor. The conversion factor is 50 for double-stranded DNA, 33 for single-stranded DNA, and 40 for RNA — these are the standard factors used by NanoDrop and other UV-Vis spectrophotometers, based on the Beer-Lambert law.
Total yield is then found by multiplying the concentration by your sample volume.
A note on accuracy
This calculator assumes a pure sample. Contaminants such as residual protein, phenol, or salts can skew A260 readings, so lab technicians typically also check the A260/A280 ratio for purity. Use this tool for general lab planning and educational purposes alongside your instrument’s own reported values.