Life, under
the lens.
The Biology Lab is a free set of biology calculators, simulations, and practice questions. From a single cell to a whole ecosystem, explore the patterns of life with interactive experiments.
Explore the lab Free to explore. No account needed. INSIDE THE LIVING WORLDMeet the cellCross two parents. See the odds.
Uppercase = dominant allele, lowercase = recessive allele. Complete dominance is assumed.
Interactive biology tools.
A bigger picture of life.
Explore cells, decode DNA, and test the patterns that connect living things.
Punnett square calculator
Cross two parents for one trait, two traits, or ABO blood type and see genotype and phenotype ratios with steps.
DNA to mRNA converter
Turn a coding strand, template strand, or mRNA into codons, tRNA anticodons, and an amino-acid chain, with the genetic code table.
Population growth calculator
Solve growth word problems, find doubling time and growth rate, and compare exponential and logistic curves.
Cell atlas
Compare organelles: where each is found, what it does, and how the parts of a cell work together.
Enzyme kinetics explorer (Michaelis–Menten)
Calculate reaction rate from Vmax, Km, and substrate concentration, then add a competitive or noncompetitive inhibitor and watch the saturation curve change.
Worksheet builder
Create a printable biology practice sheet with an optional answer key.
Popular biology calculators
Jump straight to the tool your homework needs.
Let your understanding grow.
Eight biology questions, with explanations to help each idea take root.
Explore our learning apps
One good question leads to another. Discover more free, interactive learning tools from the same maker.
Interactive Periodic Table
Meet the elements. Explore their properties and mix compounds in the chemistry sandbox.
Explore chemistryAstronomy Lab
Follow an orbit, explore Moon phases, and discover the worlds beyond our own.
Explore spaceGeometry Lab
Move a point, solve a triangle, and watch angles, shapes, and formulas make sense.
Explore mathKidsCode
Guide a robot, snap code blocks together, and make your first real Python programs.
Explore codingPhysics Lab
Launch a ball, catch a wave, and experiment with motion, forces, light, and electricity.
Explore physicsEarth Science Lab
Find an earthquake, move plates, carve a river, and follow water and rock through Earth’s cycles.
Explore earth scienceBiology Lab: frequently asked questions
Wondering about the why? Start here.
What can I do with Biology Lab?
Cross two parents in a Punnett square, translate a DNA sequence into protein, model exponential and logistic population growth, test a population for Hardy-Weinberg equilibrium, and explore nine more calculators from enzyme kinetics to energy pyramids. Each tool pairs the result with a live diagram and worked steps that update as you change the inputs.
Explore all toolsIs Biology Lab free to use?
Yes. The calculators, the cell atlas, the concept lessons, practice rounds, worksheets, and printable diagrams are all free, with no account and no sign-up. Every calculation runs in your browser, so nothing you type is sent to a server.
About the labWhich tool should I use for a genetics cross?
Start with the Punnett square calculator. It handles monohybrid crosses such as Aa × Aa (3 : 1), dihybrid crosses such as AaBb × AaBb (9 : 3 : 3 : 1), up to three genes, and ABO blood types with an optional Rh factor. To check whether real offspring counts fit the predicted ratio, follow up with the chi-square test.
Open the Punnett square calculatorCan I see how an answer is calculated?
Yes. Every calculator shows the formula with your numbers substituted and two to four worked steps, and the sixteen concept lessons explain the idea behind each tool with a numeric example and a common misconception. Change an input and watch the steps and the diagram change with it.
Read the concept lessonsCan I use these resources for teaching or practice?
Yes. Try an eight-question practice round with instant explanations across cells, genetics, molecular biology, ecology, and physiology, build a worksheet of 8, 12, or 20 questions with an optional answer key, or print a cell diagram to label and a blank Punnett grid to fill in.
Create a worksheet