One of the most overlooked tools on the AP Biology exam is the formula sheet. Many students don’t realize how much it can help — or worse, assume it covers everything when it doesn’t.
In this guide, we’ll break down what’s included, what you need to memorize, and how to practice using it efficiently.
1. What’s on the AP Biology Formula Sheet
The College Board provides a short formula sheet in the exam booklet. Here’s what you can expect:
- Chi-Square Formula χ2=∑(O−E)2E\chi^2 = \sum \frac{(O - E)^2}{E} Where O = observed value, E = expected value.
- Water Potential Formula Ψ=Ψs+ΨpΨ = Ψ_s + Ψ_p Solute potential: Ψs=−iCRTΨ_s = -iCRT
- i = ionization constant
- C = molar concentration
- R = pressure constant (0.0831 L·bar/mol·K)
- T = temperature in Kelvin
- Hardy–Weinberg Equations p+q=1p + q = 1 p2+2pq+q2=1p^2 + 2pq + q^2 = 1
- Surface Area and Volume Formulas
For cubes, spheres, and cylinders (used in diffusion, cell transport questions). - Rate and Slope Equations
Rate = change in Y ÷ change in X (applies to enzyme activity, photosynthesis, etc.).
2. What’s NOT on the Formula Sheet
You’ll still need to memorize or understand:
- Metric prefixes and conversions (µm, mm, mL, etc.)
- How to interpret and rearrange formulas (e.g., solving Ψ for solute potential alone)
- Population growth models (logistic vs. exponential curves — formulas may not be given)
