Codon Usage Calculator

Summary

This tool reads a DNA or RNA coding sequence and counts how often each of the 64 codons appears. It maps every codon to its amino acid, calculates usage frequency per thousand codons, and summarizes the overall amino acid composition — useful for comparing codon bias between organisms or optimizing synthetic gene constructs.

How it works

1. Paste or type your DNA (ATGC) or RNA (AUGC) sequence into the input box.
2. The tool reads the sequence in triplet (codon) frames starting at position 1.
3. Each triplet is looked up in the standard genetic code table.
4. Codon counts and per-thousand frequencies are computed for all 64 codons.
5. Amino acid totals are aggregated and displayed in a sortable summary table.

Use cases

• Evaluate codon bias before ordering a synthetic gene construct.
• Compare codon usage between two organisms for heterologous expression.
• Check which codons are most frequent in a CDS for tRNA availability.
• Analyze amino acid composition of a translated protein-coding region.
• Quickly verify that an ORF uses expected stop codons.
• Screen for rare codons that may slow translation in E. coli or yeast.

Frequently Asked Questions