How to use this hub
Pick your lab task first: qPCR, cell culture, genetics, or ecology.
Follow the quick path for your task, then open one tool at a time.
Use the sections below when you need a full catalog.
Quick paths
qPCR path: A260 concentration & purity, DNA/RNA converter, qPCR standard curve, then ΔCt / ΔΔCt.
Cell culture path: Hemocytometer then Cell seeding.
Microbiology path: Start with CFU/mL.
Genetics path: Punnett square, Mendelian chi-square, Hardy-Weinberg, then Wright-Fisher.
Ecology path: Growth curve, Diversity index, then Wright–Fisher.
Order is a guide. Adjust to your workflow.
Choose the genetics page by the evidence you already have
- Punnett square: start here when you know the parent genotypes and need expected offspring ratios for one planned cross.
- Mendelian chi-square: open this after a cross when you already have observed offspring counts and want to test a fixed inheritance ratio such as 3:1.
- Hardy-Weinberg: use this when your sample comes from a population and you need expected genotype frequencies from allele frequencies.
- Wright-Fisher: move here when the question is about drift across generations, not a single cross or a single equilibrium check.
Featured
- Hardy-Weinberg equilibrium calculator (expected frequency.
Calculate allele frequencies, expected genotype frequencies, χ², and p-value from observed AA/Aa/aa counts.
- ΔCt / ΔΔCt calculator (relative expression).
Paste qPCR Ct values to calculate ΔCt/ΔΔCt, log2FC, and fold change.
Assay standard curves
Suggested order: A260 concentration & purity → Protein standard curve or ELISA standard curve → Linear regression when you want a stripped-down fit check.
Open the assay standard curves guide when the main question is blank subtraction, fit choice, range interpretation, or what to report after the fit.
- Protein standard curve calculator (BCA / Bradford)
Use this for BCA or Bradford assays when you need linear or quadratic fitting, dilution-aware unknown concentrations, and exportable results.
- ELISA standard curve fitter (4PL/5PL)
Use this for immunoassay plates when you need 4PL or 5PL fitting, weighting checks, back-calculation, and extrapolation flags.
- Assay standard curves guide
Read this before or after the calculator when you need help deciding on blank handling, model choice, range checks, and report wording.
Lab practice
- Hemocytometer calculator (cells/mL & viability)
Calculate cell concentration (cells/mL) and viability (%) from hemocytometer counts and dilution. Supports improved Neubauer (10^4 factor), examples, warnings, copy, CSV/LaTeX, and share URLs.
- CFU/mL calculator (dilution, plated volume)
Calculate CFU/mL from dilution, plated volume, and colony counts. Supports 30–300 guide range, per-dilution summary, plots, CSV/LaTeX, and share URLs.
- DNA/RNA converter (ng/µL ↔ nM ↔ copies)
Convert DNA/RNA length and type into ng/µL, nM, and copies/µL. Includes total amount from volume, copy, CSV/LaTeX, and share URLs.
- NGS coverage calculator (average depth)
Estimate average coverage from target size and reads or total Gb. Adjust usable/mapping/on-target/duplicate rates, back-calculate required reads, and show ≥k× fraction (Poisson).
- NGS library concentration (ng/µL → nM)
Convert ng/µL and fragment length to nM, then plan dilution and pooling (equal volume/equal molar). Supports table input, examples, copy, CSV/JSON, and share URLs.
- Cell seeding calculator
Back-calculate required cell suspension and media volume from target cells/well or cells/cm². Includes per-well volume, overage, viability correction, copy, CSV/LaTeX, and share URLs.
- ELISA standard curve fitter (4PL/5PL)
Fit 4PL/5PL to standard points and estimate unknown concentrations. Includes weighting, residuals, back-calculation (recovery), share URLs, and CSV/JSON output.
Molecular biology
- A260 concentration & purity calculator
Calculate DNA/RNA concentration and purity ratios from A260/A280/A230 with dilution. Includes total amount, optional blank correction, copy, CSV/LaTeX, and share URLs.
- Primer Tm calculator
Calculate primer Tm and annealing temperature guides from DNA sequences with nearest-neighbor or simple formulas.
- PCR master mix calculator
Compute master mix volumes from reaction count/volume and stock/final concentrations. Supports overage, 96/384 wells, protocol text, CSV/JSON, and share URLs.
- Ligation molar ratio calculator
Calculate insert amounts from vector mass/size and molar ratio presets. Includes copy, CSV/JSON, and share URLs.
- DNA assembly mix calculator (Gibson / Golden Gate)
Calculate backbone/insert amounts and reaction volumes for assembly workflows. Includes examples, table input, copy, CSV/JSON, and share URLs.
Biochemistry
- Michaelis–Menten fitter (Km & Vmax)
Fit Michaelis–Menten to substrate concentration and initial rate, with scatter + fit curve, residuals, copy, CSV/LaTeX, and share URLs.
Genetics
Recommended order: Punnett square → Mendelian chi-square → Hardy-Weinberg → Wright-Fisher
- Punnett square generator (mono/di-hybrid)
Generate Punnett squares from parent genotypes and show genotype ratios and phenotype ratios. Includes Markdown table copy, CSV/LaTeX, and share URLs.
- Mendelian chi-square test calculator
Calculate χ², df, and p-value from observed counts and expected ratios (3:1, 9:3:3:1). Shows expected counts, contributions, charts, CSV/LaTeX, and share URLs.
- Hardy-Weinberg equilibrium calculator
Estimate allele frequencies, expected genotype frequencies, and χ² from population counts when the question is about equilibrium in a sample, not a single planned cross.
- Wright–Fisher genetic drift simulator
Move here when you want to see how finite population size, selection, or migration can change allele frequencies over generations.
Frequently asked questions
Which biology calculator should I open first?
Start from the evidence you already have. Use Punnett square for a planned cross, Mendelian chi-square for observed offspring counts, Hardy-Weinberg for population genotype frequencies, and qPCR tools when you begin with Ct values.
When should I use Hardy-Weinberg instead of Mendelian chi-square?
Use Hardy-Weinberg when expected genotype frequencies come from allele frequencies in a population sample. Use Mendelian chi-square when expected counts come from a fixed inheritance ratio such as 3:1 or 9:3:3:1.
What if my data starts with Ct values or concentration readings?
Ct values usually belong in the qPCR standard curve or ΔCt/ΔΔCt tools. Concentration or purity readings usually belong in A260, protein standard curve, or DNA/RNA conversion tools.
Are these biology tools only for teaching?
No. They are useful for teaching, protocol planning, and quick checks, but regulated or publication-grade decisions still need method review, proper controls, and the right statistical workflow.
Are my numbers uploaded when I use these pages?
Core calculations run in your browser. Sharing is explicit, so review any generated URL before sending it to someone else.
Ecology & evolution
Suggested order: Growth curve → Doubling time → Logistic K (upper limit)
- Growth curve fitter (exponential & logistic)
Fit exponential and logistic growth to time-series data to estimate r, doubling time, and K. Includes residuals, model comparison, CSV/LaTeX, and share URLs.
- Diversity index calculator (Shannon & Simpson)
Compute Shannon and Simpson indices from category counts. Shows ln/log2/log10, D/1−D/1/D, Hill numbers, evenness, examples, copy, CSV/JSON, and share URLs.
- Wright–Fisher genetic drift simulator
Simulate genetic drift with N, p0, generations, and replicates. Visualize trajectories and fixation/extinction rates, with selection/mutation/migration options.
All biology tools
- A260 Calculator (DNA/RNA Concentration & Purity).
Use A260/A280/A230 and dilution to estimate DNA/RNA concentration (ng/µL) plus A260/280 and A260/230 purity ratios.
- Beta diversity calculator (Jaccard / Bray–Curtis).
Compute beta diversity between samples using Jaccard (presence/absence) or Bray–Curtis (abundance).
- Cell seeding calculator | cells/well → required volume.
Calculate required cell suspension and media volume from target cells/well (or cells/cm²), number of wells, volume.
- Centrifuge converter (rpm ↔ RCF ×g) | by rotor radius.
Convert between centrifuge speed (rpm) and relative centrifugal force (RCF, ×g) using rotor radius (mm/cm/in).
- CFU/mL Calculator | Colony Count, Dilution & Plated Volume.
Calculate CFU/mL from colony count, dilution, and plated volume.
- Diversity index calculator (Shannon & Simpson).
Calculate diversity indices from category counts.
- DNA/RNA Concentration Converter.
Convert DNA or RNA concentration between ng/µL, nM, and copies/µL from fragment length and type.
- ELISA standard curve fitter (4PL/5PL).
Fit 4PL/5PL curves to ELISA standards, estimate unknown concentrations, and review weighting, residuals.
- Genetic drift simulator (Wright–Fisher) | allele.
Simulate genetic drift with the Wright–Fisher model.
- Gibson Assembly Calculator & DNA Assembly Mix.
Plan Gibson or Golden Gate DNA assembly mixes.
- Growth curve fitter (exponential & logistic).
Fit exponential and logistic growth to time-series data and estimate growth rate r, doubling time, and carrying.
- Hemocytometer calculator (cells/mL & viability).
Calculate cell concentration (cells/mL) and viability (%) from hemocytometer counts and dilution.
- IC50/EC50 calculator (4PL/5PL curve fit) | Dose–response.
Paste concentration–response data and estimate IC50/EC50 (the 50% point) with 4PL/5PL curve fitting.
- Kd calculator | Binding curve fit (one site / Hill).
Fit binding data with one-site or Hill models to estimate Kd.
- Ligation molar ratio calculator | Vector:insert amounts.
Calculate required insert mass (ng) and volume (µL) from vector mass, length, and desired molar ratio (e.g., 1:3).
- Mendelian ratio chi-square test calculator.
From observed counts and expected ratios (3:1, 9:3:3:1, etc.), calculate χ², df, and p-value.
- Michaelis–Menten fitter (Km, Vmax) | nonlinear fit.
Estimate Km and Vmax by nonlinear fitting of the Michaelis–Menten equation from substrate [S] and initial rate v.
- MOI Calculator | Infection Rate & Target Volume Guide.
Calculate MOI from cell count, infectious titer, and inoculum volume.
- NGS coverage calculator (average depth).
Estimate average NGS coverage depth.
- NGS library concentration (ng/µL → nM) | dilution.
Convert NGS library concentration from ng/µL and fragment length to nM, then calculate normalization dilutions.
- PCR master mix calculator | reactions, concentrations.
Calculate PCR/qPCR master mix volumes from reaction volume/count and stock/final concentrations.
- PCR Primer Tm Calculator | Melting & Annealing Temperature.
Calculate primer melting temperature (Tm) and PCR annealing temperature (Ta) from DNA sequences.
- Protein standard curve calculator (BCA / Bradford).
Build a protein assay standard curve for BCA or Bradford data, fit linear or quadratic models, and estimate unknown.
- Punnett square generator (1- and 2-gene).
Generate a Punnett square from parent genotypes (AA/Aa/aa, AaBb, etc.) and summarize genotype proportions (%/ratio).
- qPCR standard curve calculator.
Build a qPCR standard curve from Quantity and Ct, calculate slope, intercept, R², and PCR efficiency (%).
Where to go next
- Hardy-Weinberg
Use this when you need expected genotype frequencies from allele frequencies in a population sample.
- qPCR standard curve
Open this when your data starts with Ct values and dilution standards rather than genotype counts.
- Chemistry calculators
Move here for buffers, titration, Beer-Lambert, or other lab calculations that are not biology-specific.
- Science & engineering hub
Return to the broader science hub when you need to switch from biology into chemistry, physics, or astronomy tools.