4PL ELISA Curve Fitter
Paste assay data, fit a 4-parameter logistic curve, batch-calculate unknowns. Up to 3 curves at once. Everything stays in your browser.
1. Data Entry
Up to 3 datasets — use the tabs below to add, switch, rename (double-click a tab name), or remove one. Paste tab/comma/space-separated data. Column 1 = X (concentration), columns 2+ = Y replicates (OD). One row per X value. Straight from Excel.
2. Parsed Data Verification
3. Fit Results
Fitted equation (symbolic):
Y = D + (A − D) / (1 + (X / C)^B)
where A = min, D = max, C = EC50, B = Hill slope
Y = D + (A − D) / (1 + (X / C)^B)
where A = min, D = max, C = EC50, B = Hill slope
Cite this tool:
4. Batch Calculator
Paste a column of values. Get a column of results back. Ready to paste into Excel.
Results will appear here...