About the toolkit

Show the biology between the data and the conclusion.

This is a free, static set of biology calculation and experimental-data tools for high-school and introductory university study.

Level labels

SL/HL labels are based on the current IB Biology syllabus where practical. A calculator is a support tool, not a substitute for choosing a defensible method or explaining biological meaning.

Statistics

The regression tool uses ordinary least squares. The independent t-test uses Welch’s unequal-variance form by default; the paired option analyses within-pair differences. Chi-squared p-values use the usual continuous chi-squared approximation. Always check whether the design and assumptions justify the test.

Biological variation

Biological systems often show genuine variation. SD, SE, error bars, r, R² and p-values answer different questions; the site keeps them separate rather than treating them as interchangeable “error”.

Numerical limits

The browser uses standard JavaScript floating-point arithmetic. Intermediate calculations retain more digits than normally displayed. Use the worked steps to verify the model and units.

Independent resource

This site is not affiliated with or endorsed by the International Baccalaureate Organization or any school. Paper 1B practice content is original and does not reproduce examination questions.