How to use the mark–recapture population calculator
Estimate population size with the Lincoln–Petersen method. Enter marked in first capture, total in second capture, marked recaptured in the fields above; the estimated population is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- M — Marked in first capture
- C — Total in second capture
- R — Marked recaptured
Worked example
With marked in first capture = 50, total in second capture = 60, marked recaptured = 12, the calculator gives estimated population ≈ 250.
Frequently asked questions
What is the formula for the mark–recapture population calculation?
Estimated population = M × C / R. Here M is marked in first capture, C is total in second capture, R is marked recaptured.
What inputs do I need for the mark–recapture population estimator calculator?
You need marked in first capture, total in second capture, marked recaptured. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.