← Back to ResearchRanked

GRAVYCalc Protein Hydropathy

Multi-FASTA · Kyte-Doolittle scale · batch GRAVY

English 简体 繁體

Input FASTA protein sequence(s)

Paste sequences in FASTA format: each line starting with ">" is a header line and starts a new record - multiple sequences require headers; a single sequence may omit it. You can also drop a .fasta / .txt / .gz file onto the box.

Options

Show sequences:
These characters are excluded from the length and the average (e.g. stop * or gap -); any other non-standard character is flagged as a warning.
Decimal sign:

Results

Kyte-Doolittle amino-acid hydropathy values

Values from Kyte & Doolittle, J. Mol. Biol. 157 (1982) 105-132, Table 1: positive = hydrophobic (favours the membrane interior), negative = hydrophilic (favours the solvent). GRAVY = sum of hydropathy values over the sequence ÷ number of residues.

What this tool is

GRAVYCalc computes the grand average of hydropathy (GRAVY) of protein sequences: the sum of the Kyte-Doolittle hydropathy values of all residues divided by the sequence length. GRAVY is the most-quoted single descriptor of a protein's overall character - membrane proteins are rich in I, L, V, F and M and score clearly positive, while soluble globular proteins usually score negative. It mirrors gravy-calculator.de: same input format, same ignore-char, separator and decimal-sign options.

Everything is computed in your own browser: the hydropathy table ships with the page, there is no backend and nothing is uploaded. Your input is kept in local storage, and even genome-scale input is a single pass of additions - done in milliseconds.

Features

How to use it

  1. Paste your FASTA sequences into the box (every record needs its ">" header line), or click "Import from file…" / drop a file onto the box.
  2. Put stop or gap characters into "Ignore chars" if they should not count; switch "Show sequences" on to proof-read.
  3. The table updates live with length and GRAVY per record; non-standard characters are counted in the warning column.
  4. Pick the separator and decimal sign, then "Copy results" or "Download file" to take the whole table away.

FAQ

What exactly is GRAVY and how do I read it?
GRAVY = Σ(residue hydropathy values) ÷ sequence length, on the Kyte & Doolittle (1982) scale (I 4.5 is the most hydrophobic, R -4.5 the most hydrophilic). A positive GRAVY means the sequence is overall hydrophobic - typical of membrane proteins (most are above 0, strongly transmembrane ones above 1); a negative GRAVY means hydrophilic, typical of soluble proteins. It is only an average: a sequence with one hydrophobic and one hydrophilic half can land near 0, so pair it with transmembrane prediction when it matters.
What happens to X, B, Z, U, *, - in my sequences?
Characters outside the 20 standard amino acids fall into two classes: anything listed in "Ignore chars" (by default * and -) is simply excluded from the count; everything else is counted per character in the warning column. The length only ever counts standard residues. To skip ambiguity codes as well, add X and friends to the ignore box.
Are my sequences uploaded?
No. The page is fully static with no backend; the computation runs locally in your browser and the input only ever goes to your browser's local storage. Unpublished sequences are safe.
Do I have to remove numbering and spaces?
No. Whitespace and digits in sequence lines (e.g. line numbers copied out of a PDF) are discarded automatically - only letters count. Header lines are kept verbatim as the record name in the results table.
What format is the export?
A plain-text table with four columns: number, name/description, length, GRAVY. Tab pastes straight into Excel, comma produces a .csv, and the decimal sign can be switched to a comma for European locales.

More tools on this site

Pure front-end · zero dependencies · free · 中文 / 繁體 / English