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
# Contigs
N50
L50
N90
L90
Min / Max
Mean / Median

Contig length preview

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