Sequentica
Bioinformatics utilities

N50 Calculator

Paste or upload FASTA contigs to compute N50/L50 and N90/L90. Runs locally in your browser (no server upload).

Input

Accepted extensions: .fa .fasta .fna .fas .txt
Input rules
  • Each FASTA record must start with >.
  • Whitespace is ignored.
  • Characters - and . are ignored (alignment gaps).
  • Zero-length records are automatically skipped.

Results

Load a sample or provide FASTA to begin.
Total length
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# Contigs
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N50
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L50
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N90
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L90
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Min / Max
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Mean / Median
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Contig length preview

# Header Length
Privacy: Computation happens entirely in your browser. Your FASTA sequences are not uploaded or stored.