AP Biology Equations and Formulas Sheet 2026

AP Biology Equations and Formulas Sheet 2026

AP Biology Equations and Formulas Sheet 2026 provides essential formulas and equations for students preparing for the AP Biology exam. This reference includes statistical analysis, population growth equations, and the Hardy-Weinberg principle, crucial for understanding genetics and evolution. It also covers water potential calculations and surface area and volume formulas, which are vital for cellular biology. Designed for AP Biology students, this sheet serves as a quick reference guide for key concepts and calculations needed for the May exam.

Key Points

  • Includes key statistical equations for AP Biology exams.
  • Covers population growth models including exponential and logistic growth.
  • Details the Hardy-Weinberg equations for genetic equilibrium.
  • Explains water potential calculations essential for plant biology.
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NOTE: You may use any blank space in this booklet for scratch work during the exam. Proctors should collect this
reference information at the conclusion of the exam.
Name: ___________________________________________________
AP
®
Biology
2026 EXAM REFERENCE INFORMATION
AP
®
BIOLOGY EQUATIONS AND FORMULAS
Statistical Analysis and Probability
x = sample mean
n = sample size
s = sample standard deviation (i.e., the sample-based
estimate of the standard deviation of the
population)
o = observed results
e = expected results
∑ = sum of all
Degrees of freedom are equal to the number of
distinct possible outcomes minus one.
Mean Standard Deviation
Standard Error of the Mean Chi-Square
Chi-Square Table
p
value
Degrees of Freedom
1 2 3 4 5 6 7 8
0.05 3.84 5.99 7.81 9.49 11.07 12.59 14.07 15.51
0.01 6.63 9.21 11.34 13.28 15.09 16.81 18.48 20.09
Laws of Probability
If A and B are mutually exclusive, then:
PP(A or B) =+(A)(P B)
If A and B are independent, then:
PP(A andB)(=×A) P(B)
Hardy–Weinberg Equations
pp
22
++21qq= p = frequency of allele 1 in a population
pq+=1 q = frequency of allele 2 in a population
Metric Prefixes
Factor Prefix Symbol
10
9
giga
G
10
6
mega M
10
3
kilo k
10
−1
deci d
10
−2
centi c
10
−3
milli m
10
−6
micro µ
10
−9
nano n
10
−12
pico p
Mode = value that occurs most frequently in a data set
Median = middle value that separates the greater and lesser halves of a data set
Mean = sum of all data points divided by number of data points
Range = value obtained by subtracting the smallest observation (sample minimum) from the greatest (sample maximum)
 1AP Biology
© 2025 College Board
Rate
dY
dt
Population Growth
dN
=−BD
dt
Exponential Growth
dN
= rN
dt
max
Rate and Growth
Logistic Growth
dY = amount of change
dt = change in time
dN = change in population size
B = birth rate
D = death rate
N = population size
K = carrying capacity
r
max
= maximum per capita
growth rate of population
Simpson’s Diversity Index
Diversity Index =
n = total number of organisms of a particular species
N = total number of organisms of all species
Water Potential ( )
pressure potential
solute potential
The water potential will be equal to the
solute potential of a solution in an open
container because the pressure potential of
the solution in an open container is zero.
The Solute Potential of a Solution
−iCRT
i = ionization constant (1.0 for sucrose
because sucrose does not ionize in
water)
C = molar concentration
R = pressure constant
(R = 0.0831 liter bars/mole K)
T = temperature in Kelvin
()
°+C 273
Surface Area of a Sphere
Surface Area of a Rectangular Solid
SA =+22lh lw + 2wh
Surface Area of a Cylinder
Surface Area of a Cube
SA = 6s
2
Volume of a Sphere
Volume of a Rectangular Solid
Vl= wh
Volume of a Cylinder
Volume of a Cube
Vs=
3
Surface Area and Volume
r = radius
l = length
h =height
w = width
s = length of one
side of a cube
SA = surface area
V = volume
 2AP Biology
© 2025 College Board
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End of Document
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Faqs of AP Biology Equations and Formulas Sheet 2026
What statistical analysis formulas are included in the AP Biology sheet?
The AP Biology Equations and Formulas Sheet includes essential statistical analysis formulas such as the sample mean, sample standard deviation, and the chi-square test. These formulas are crucial for analyzing data in biological experiments and understanding variability within populations. The sheet also provides a chi-square table for quick reference to p-values and degrees of freedom, which helps in hypothesis testing.
How does the Hardy-Weinberg principle apply to population genetics?
The Hardy-Weinberg principle describes the genetic variation in a population at equilibrium. It states that allele and genotype frequencies will remain constant from generation to generation in the absence of evolutionary influences. This principle is foundational for understanding population genetics, as it allows biologists to predict genetic variation and assess whether a population is evolving. The equations provided in the sheet help students calculate allele frequencies and understand the conditions necessary for genetic equilibrium.
What are the key equations for population growth in AP Biology?
The AP Biology Equations and Formulas Sheet outlines two primary models of population growth: exponential and logistic growth. The exponential growth model is represented by the equation dN/dt = rN, where N is the population size and r is the maximum per capita growth rate. In contrast, the logistic growth model accounts for environmental carrying capacity with the equation dN/dt = rN(K-N)/K, where K represents the carrying capacity. Understanding these models is essential for studying population dynamics and ecology.
What is the significance of water potential in plant biology?
Water potential is a critical concept in plant biology that determines the direction of water movement within plants. The AP Biology sheet explains that water potential is the sum of pressure potential and solute potential, with the formula Ψ = Ψp + Ψs. This concept is essential for understanding how plants absorb water from the soil and how they maintain turgor pressure. It also helps explain phenomena such as osmosis and the movement of water through plant tissues.