Magnification
I image size, A actual size (same units).
M = I / A IB Middle Years Programme 2026
🧬 IB MYP Biology Formula Sheet
Essential formulas for cells, genetics, ecology, and biological calculations across MYP Years 1-5.
Cells Genetics Ecology
Our formula sheets are free to download — save this one as PDF for offline revision.
Aligned with the latest 2026 syllabus and board specifications. This sheet is prepared to match your exam board’s official specifications for the 2026 exam series.
Understand Biological Relationships
This formula sheet covers fundamental biology relationships from MYP Years 1-5, helping you solve problems involving cells, genetics, and ecosystems.
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Cell calculations
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Genetics formulas
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Ecology relationships
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Data analysis
Microscopy & magnification
Image size, actual size, and magnification.
Actual size
Rearrangement.
A = I / M Image size
Rearrangement.
I = M × A Topic Focus
Units
- Convert µm to mm (÷ 1000) or nm to µm (÷ 1000) before dividing or multiplying.
- Show working: quote formula and substitute numbers with units.
Surface area, volume & diffusion
SA:V ratio and exchange surfaces.
Surface area to volume ratio
Cube side length L.
SA:V = 6 L² / L³ = 6 / L Sphere (reference)
radius r.
V = (4/3) π r³ SA = 4 π r² Fick’s law (conceptual)
Rate of diffusion ∝ surface area × concentration difference / thickness.
rate ∝ A × Δc / d Topic Focus
Exchange
- Smaller cells or flattened shapes increase SA:V relative to volume.
- Adaptations (villi, alveoli, root hairs) increase surface area for diffusion/transport.
Population growth & sampling
Population estimates and growth patterns.
Population estimate (capture–recapture)
Lincoln–Peterson style.
N ≈ (M × C) / R Mean
Sample mean.
x̄ = Σ x / n Percentage change (population)
Compare to earlier count.
% change = (new − old) / old × 100% Topic Focus
Sampling
- Random sampling reduces bias; large sample size improves reliability.
- Marking must not harm survival or behaviour in capture–recapture.
Cardiovascular & fitness
Cardiac output and related measures.
Cardiac output
SV stroke volume (ml), HR heart rate (beats/min).
CO = SV × HR Stroke volume (from CO)
Rearrangement.
SV = CO / HR Topic Focus
Context
- During exercise, CO increases by increasing HR and often SV.
- Units must be consistent (e.g. ml/min for CO if SV in ml and HR in bpm).
Photosynthesis & respiration (summary)
Word equations and mole ratios (where assessed).
Photosynthesis (word)
Glucose and oxygen from carbon dioxide and water (light energy).
carbon dioxide + water → glucose + oxygen Aerobic respiration (word)
Energy release in cells.
glucose + oxygen → carbon dioxide + water (+ energy) Anaerobic respiration (animals)
Lactic acid pathway.
glucose → lactic acid (+ energy) Topic Focus
Bioenergetics
- Link rate of respiration to oxygen demand and surface area for gas exchange.
- Compare anaerobic vs aerobic yield of energy in context of exercise.
Genetics & inheritance
Probability in monohybrid crosses.
Expected ratio (heterozygous × heterozygous)
One gene, complete dominance.
Phenotypic ratio 3 : 1 (dominant : recessive) Probability (independent assortment)
Multiply probabilities for combined events.
P(A and B) = P(A) × P(B) (if independent) Topic Focus
Punnett squares
- Gametes must be shown separately before combining.
- State whether you are giving a genotypic or phenotypic ratio.
How to Use This Formula Sheet
Boost your Cambridge exam confidence with these proven study strategies from our tutoring experts.
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Use Correct Units
Always check units match in calculations. Convert between mm, cm, m, and μm as needed.
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Draw Diagrams
Sketch Punnett squares, cell structures, or ecosystems to visualize relationships before calculating.
Formula sheet FAQ
Quick answers about this free PDF, how to use it for exam revision, and how it relates to your official syllabus.
Is the IB MYP Biology Formula Sheet 2026 free to download as a PDF?
Yes. This Tutopiya formula sheet is free to use and you can download it as a PDF from this page for offline revision. There is no payment or account required for the PDF download.
What Biology topics and equations does this formula sheet cover?
This page groups key Biology formulas in one place for revision. Essential IB Middle Years Programme Biology formulas covering cells, genetics, ecology, and biological calculations for MYP Years 1-5 (ages 11-16). Always cross-check with your official syllabus and past papers for your exam session.
Can I use this instead of the official exam formula booklet in the exam?
No. In the exam you must follow only what your exam board allows in the hall—usually the official formula booklet or data sheet where provided. This page is a revision and teaching aid, not a replacement for board-issued materials.
Who is this formula sheet for (Middle School)?
It is written for students preparing for assessments at Middle School in Biology, including classroom revision, homework support, and independent study. Teachers and tutors can also share it as a quick reference.
How should I revise with this formula sheet?
Work through past paper questions, quote the correct formula before substituting values, and check units and notation every time. Pair this sheet with timed practice and mark schemes so you see how examiners expect working to be set out.
Where can I get more help with Biology revision?
Explore Tutopiya’s study tools, past paper finder, and revision checklists linked from our tools hub, or book a trial lesson with a subject specialist for personalised support alongside this formula reference.
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Formulas align with IB MYP Biology curriculum for Years 1-5 (ages 11-16).
Always show your working, include units, and check that answers make biological sense.