DNA Concentration Calculator

The DNA Concentration Calculator estimates double-stranded DNA concentration from A260 absorbance, using the standard factor of 50 µg/mL per absorbance unit and your dilution factor.

Formula

Concentration = A260 × Factor × Dilution (dsDNA factor ≈ 50 µg/mL)
  • Use 50 µg/mL for double-stranded DNA, 40 for RNA, and 33 for single-stranded DNA.
  • µg/mL is numerically the same as ng/µL.

A260 = 0.5, dilution 1×

Inputs
  • A260 Absorbance: 0.5
  • Dilution Factor: 1
  • Factor (µg/mL per A260): 50

0.5 × 50 × 1 = 25 µg/mL (25 ng/µL) of dsDNA.

Frequently asked questions

What factor should I use?
50 µg/mL per A260 for dsDNA, 40 for RNA, and 33 for single-stranded oligonucleotides.