Tools · calculator
GC Content Calculator
Count bases and compute GC% and AT/AU%.
Instructions
Paste a DNA or RNA sequence to analyze composition.
Sequences are limited to 20000 characters after cleaning. Shareable URLs encode at most 400 characters.
Interactive tool
Example
Try the built-in example button in the tool panel, or use classroom sequences such as ATGGAGTTTTAA for DNA tools and Aa × Aa for Punnett squares.
How to interpret results
Results are deterministic educational calculations based on standard molecular biology and Mendelian rules. Read warnings and assumptions printed with each result. These tools do not provide clinical, diagnostic, or research-grade sequence interpretation.
Biological background
Count bases and compute GC% and AT/AU%. Connect the outputs to the related learning topics below for packaging, expression, or inheritance context.
Limitations
- Deterministic classroom models only — not AI guesses and not clinical advice.
- Ambiguous IUPAC bases, alternative genetic codes, linkage, and epigenetic effects are out of scope unless a tool explicitly states otherwise.
- Sequence length and request size are limited to protect the server.
- Huge sequences are not placed into shareable URLs.
Related learning topics
- DNA — DNA stores genetic information as a sequence of nucleotide bases in a double helix.
- DNA structure — DNA structure features a sugar-phosphate backbone and complementary base pairs forming a double helix.
Related tools
Continue on Chromatin.net
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Source / methodology note
Calculators use verified deterministic rules (Watson–Crick base pairing, the standard genetic code, Mendelian Punnett logic, and Hardy–Weinberg algebra). Explorers use Chromatin.net’s educational content model. See methodology.