Calibration Curve Calculator Formula
Understand the math behind the calibration curve calculator. Each variable explained with a worked example.
Formulas Used
Unknown Concentration
concentration = (signal - intercept) / slopeBack-Calculated Signal
predicted_signal = slope * ((signal - intercept) / slope) + interceptVariables
| Variable | Description | Default |
|---|---|---|
slope | Calibration Slope (m) | 2500 |
intercept | Calibration Intercept (b) | 0.05 |
signal | Measured Signal (y) | 1.3 |
How It Works
Linear Calibration Curve
A calibration curve relates instrument signal to analyte concentration. With a linear model y = mx + b, an unknown concentration is found by inverting this relationship.
Formula
c_unknown = (y_measured - b) / m
where y is the measured signal, m is the slope from standard curve regression, and b is the y-intercept. The calibration curve should be established from at least 5 standard concentrations spanning the expected range.
Worked Example
A calibration with slope = 2500 (signal/M), intercept = 0.05, and measured signal = 1.3.
slope = 2500intercept = 0.05signal = 1.3
- 01c = (1.3 - 0.05) / 2500
- 02c = 1.25 / 2500 = 0.000500 M = 0.500 mM
Ready to run the numbers?
Open Calibration Curve Calculator