His-Tagged Protein Hydrophobicity (GRAVY) Calculator

Score the GRAVY hydropathy of a his-tagged protein from its amino-acid sequence. Positive = hydrophobic, negative = hydrophilic. 100% in-browser — your sequence is never uploaded.

GRAVY = mean Kyte–Doolittle index

Protein / peptide sequence (1-letter)

-0.228

GRAVY hydropathy

hydrophilic

Character

Residues

1
GRAVY = Σ(Kyte–Doolittle index) ÷ length
-17.1 ÷ 75 = -0.228
2
Negative → hydrophilic overall

His-Tagged Protein: Positive = hydrophobic, negative = hydrophilic.

🔒 100% client-side — your data is computed in the browser and never uploaded.

Cite this tool

ToolJolt. His-Tagged Protein Hydrophobicity (GRAVY) Calculator. ToolJolt Chemistry & Lab Tools; 2026. https://tooljolt.com

Need a fast, reliable his-tagged protein hydrophobicity (gravy) calculator? This free tool computes the answer the moment the page loads and updates live as you type — no sign-up, no installs.

About His-Tagged Protein Hydrophobicity (GRAVY) Calculator

Score the GRAVY hydropathy of a his-tagged protein from its amino-acid sequence. Positive = hydrophobic, negative = hydrophilic. 100% in-browser — your sequence is never uploaded. The calculation uses GRAVY = mean Kyte–Doolittle index. Why accuracy here pays off: The extinction coefficient sets every A280 concentration you report; the pI decides your ion-exchange and solubility strategy. These numbers underpin purification and quantitation. His-Tagged Protein: Positive = hydrophobic, negative = hydrophilic. Mistakes that trip people up: ignoring post-translational modifications; forgetting cystine (disulfide) contributions to ε280; using reduced vs oxidized ε in the wrong context. No account, no upload, no tracking of your inputs — the result is generated on your machine, which makes it reproducible, private and citable in published work.

How to use His-Tagged Protein Hydrophobicity (GRAVY) Calculator

1Enter your input values.
2Read the headline result and the supporting figures, which recompute as you type.
3Open “Worked example with your numbers” to see the substituted formula step by step.
4Copy the result, or use the cite-this-tool snippet for your methods section.

Why use His-Tagged Protein Hydrophobicity (GRAVY) Calculator?

✓Mobile-friendly and completely free, with no sign-up or usage caps
✓Built on a sourced, unit-tested formula for protein and peptide characterization
✓Links to related protein and peptide characterization calculators so you can finish the whole workflow
✓Copy-ready result and a one-line “cite this tool” snippet for your methods section
✓Designed for protein biochemists, structural biologists and assay developers who need a trustworthy answer fast

Frequently asked questions

Any tips specific to this calculation?+

His-Tagged Protein: Positive = hydrophobic, negative = hydrophilic. Also watch out for: ignoring post-translational modifications and assuming pI from sequence equals experimental pI exactly.

Is this his-tagged protein hydrophobicity (gravy) calculator free to use?+

Yes. It is completely free, needs no sign-up, and runs entirely in your browser — there are no usage limits.

What formula does it use?+

It uses GRAVY = mean Kyte–Doolittle index The full worked example is shown beneath the result so you can verify each step.

What are the most common mistakes here?+

In protein and peptide characterization, watch for: forgetting cystine (disulfide) contributions to ε280; using reduced vs oxidized ε in the wrong context; assuming pI from sequence equals experimental pI exactly; ignoring post-translational modifications. This tool shows the working so you can catch these before they cost an experiment.

Does my data leave my device?+

No. All computation happens locally in your browser. Nothing you enter — sequences, concentrations or measurements — is uploaded to any server, so it is safe for confidential work.

Can I cite this tool?+

Yes — use the “Cite this tool” snippet on the page. Many users link these calculators from methods sections, lab SOPs and teaching materials.

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