Toolyard

DNA Statistics

How to count bases and GC content

  1. Paste one or more DNA sequences, as plain text or FASTA.
  2. The counts of A, C, G and T, the GC and AT content, purines, pyrimidines and all 16 dinucleotides appear for each sequence.
  3. Copy output or Download saves the result.

Frequently asked questions

How is GC content worked out?

G plus C divided by the length of the sequence. Ambiguity codes such as N count towards the length under Other, so a sequence with many Ns shows a lower GC content.

Is my sequence uploaded?

No. Everything runs in your browser, so your sequences never leave your device.

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