📈 Dose‑Response Curve Fitter

Fit a 4‑parameter logistic (4PL) model to your data. Calculate IC50, EC50, Hill slope, and more.

1 Input Data
2 Fit Model
3 Results & Plot

Step 1: Enter your dose‑response data

Paste or type your data as two columns: concentration (X) and response (Y).
Separate values with spaces, tabs, or commas. One pair per line.

Enter data to see preview…

Step 2: Fit the 4‑parameter logistic model

The model: Y = Bottom + (Top − Bottom) / (1 + (X / EC50)−HillSlope)

🤖 Automatic fitting: We use iterative least‑squares optimisation to find the best parameters for your data.
Leave blank for automatic estimation.
Leave blank for automatic estimation.
Leave blank for automatic estimation.
Leave blank for automatic estimation.
(recommended for typical dose‑response curves)

Step 3: Results