📈 Dose‑Response Curve Fitter

Fit a 4‑parameter logistic model, calculate IC50/EC50, Hill slope, and R².

1Input Data

2Fit Model

3Results & Plot

Step 1: Enter your dose‑response data

Two columns: concentration (X) and response (Y). Separate with spaces, tabs, or commas.

Data

Data preview

Enter data to see preview…

Step 2: Fit the 4‑parameter logistic model

Y = Bottom + (Top − Bottom) / (1 + (X/EC50)^−HillSlope)

🤖 Automatic fitting: Iterative least‑squares optimisation.

Top (optional)

Bottom (optional)

EC50 / IC50 (optional)

Hill slope (optional)

Log‑transform X‑axis for fitting

Step 3: Results

 WHAT IT DOES:

Fit a 4‑parameter logistic (4PL) model to your dose‑response

data. Automatically calculates:

  • IC50 / EC50 (the concentration at 50% effect)

  • Hill slope (steepness of the curve)

  • Bottom and Top values (minimal and maximal response)

  • R² (goodness of fit)

  • Displays an interactive chart with your data and the fit

WHO IT'S FOR:

• Pharmacology students learning dose‑response concepts

• Researchers analysing drug efficacy data

• Scientists presenting inhibition curves

• Anyone working with concentration-response experiments

HOW TO USE IT:

1. Paste your data as two columns: concentration and response

2. (Optional) Adjust the fitting parameters

3. Click "Fit & Show Results"

4. View your IC50/EC50, Hill slope, and R²

5. Examine the interactive chart showing your data and the fit