Click here to explore thousands of examiner marked IA, EE and TOK exemplars!
While the IB Biology syllabus doesn’t provide a formula booklet, there are several key formulae that are essential to know for your exams. In this post, we’ll highlight the formulae you should be familiar with.
IB Biology Formula Booklet
| Name | Formula | Notes/Annotations |
|---|---|---|
| Mean | Mean = Σx/n where Σx is the sum of all data values and n is the number of data values | Remember: Sensitive to extreme values (outliers), which can skew the mean. |
| Percentage change | % change = [(Final value − Initial value) ÷ Initial] × 100 | Common mistake: Dividing by the final value instead of the initial value; always use the initial value in the denominator. |
| Magnification | M = I ÷ A where I is the Image size (measured with a ruler) and A is the Actual size (according to scale bar) | Remember: You can rearrange the formula to find the image size or the actual size. |
| BMI | BMI = mass (kg) ÷ [height (m)]2 | Remember: BMI is a general guideline and may not account for muscle mass or body composition. |
| Energy in food | Energy (kJ/g) = (Water mass × ΔT × 4.2) ÷ Mass of food where ΔT is the temperature change of the water (in °C) | Remember: 4.2 represents the specific heat capacity of water in J/g°C; convert to kJ by dividing by 1000 if needed. |
The Fast Track To Your
Best IB Coursework & College Essays
All content on this website has been developed independently from and is not endorsed by the International Baccalaureate Organization. International Baccalaureate and IB are registered trademarks owned by the International Baccalaureate Organization.