# Gene Penetrance & Expressivity Calculator Estimate penetrance f = affected carriers / total carriers with nonpenetrance, plus a severe/moderate/mild expressivity breakdown among affected carriers. Derived from Wright, Griffiths, OMIM, StatPearls. Educational use only. > Canonical page: https://elysiatools.com/en/tools/gene-penetrance-calculator - **Category:** Education - **Keywords:** penetrance, penetrance calculator, incomplete penetrance, expressivity, variable expressivity, genotype phenotype relationship, neurofibromatosis penetrance, polydactyly, mendelian genetics, genetics ## Overview Calculate gene penetrance from affected and total genotype carrier counts, then summarize severe, moderate, and mild expressivity among affected carriers. The results are provided for educational use only. ## Inputs - **Total genotype carriers** (number): Total number of individuals known to carry the genotype. - **Affected (phenotype present)** (number): Carriers who show the phenotype in any degree. - **Severe expression cases** (number): Affected carriers with severe expression. - **Mild expression cases** (number): Affected carriers with mild expression. - **Decimal Places** (number) ## When to use - Estimate complete or incomplete penetrance in a genetics exercise or study dataset. - Compare phenotype severity among carriers who express a trait. - Demonstrate the difference between penetrance and variable expressivity. ## How it works - Enter the total number of genotype carriers and the number who show the phenotype. - Enter the affected carriers classified as severe and mild; moderate cases are calculated as the remaining affected carriers. - The calculator divides affected carriers by total carriers to find penetrance and calculates nonpenetrance as 1 minus penetrance. - It returns the penetrance, nonpenetrance, and expressivity proportions in JSON, rounded to the selected number of decimal places. ## Use cases - Calculate penetrance and nonpenetrance from observed carrier counts. - Summarize severe, moderate, and mild phenotype expression in an affected group. - Create worked examples for Mendelian genetics and genotype-phenotype lessons. ## Frequently asked questions ### What is gene penetrance? Penetrance is the proportion of genotype carriers who show the associated phenotype. ### How is nonpenetrance calculated? Nonpenetrance equals 1 minus penetrance, or unaffected carriers divided by total carriers. ### How are moderate expression cases determined? Moderate cases are the affected carriers remaining after severe and mild cases are subtracted. ### What is the difference between penetrance and expressivity? Penetrance indicates whether a phenotype appears, while expressivity describes its severity among affected carriers. ### Can this calculator provide medical or genetic counseling? No. It is an educational calculator and does not replace clinical assessment or genetic counseling. ## Related tools - [Absorbance↔Transmittance Converter (A = −log₁₀T)](https://elysiatools.com/en/tools/absorbance-transmittance-converter): Convert A ↔ %T ↔ T with A = −log₁₀(T) and %T = 100·T; returns all three representations for spectrophotometry work. - [PCR Annealing Temperature Calculator (Ta = Tm − 5°C)](https://elysiatools.com/en/tools/annealing-temperature-calculator): PCR Ta by the simple rule (lower primer Tm − 5°C) or the Rychlik 1990 formula (0.3·Tm_primer + 0.7·Tm_product − 14.9), with a ±3°C gradient window and primer-Tm mismatch warning. Derived from Rychlik 1990, Innis & Gelfand 1990, Lorenz 2012. Lab-planning use only. - [Autosomal Dominant Pedigree Analyzer](https://elysiatools.com/en/tools/autosomal-dominant-pedigree): Compute AD offspring risk (Aa×aa 1:1, Aa×Aa 3:1, AA×any all affected), chi-square fit of observed children, and hallmark checks including male-to-male transmission that rules out X-linked dominant. Derived from Griffiths, Hartl & Clark 2007, StatPearls, OMIM. Educational use only. - [Autosomal Recessive Inheritance Risk Calculator](https://elysiatools.com/en/tools/autosomal-recessive-risk): Compute per-child and cumulative autosomal recessive disease risk from parental statuses (carrier / affected / non-carrier / unknown via population carrier rate), including the 2/3 carrier rule. Derived from Griffiths, Hartl & Clark 2007, StatPearls. Educational use only. - [Hemocytometer Cell Counter (cells/mL)](https://elysiatools.com/en/tools/cell-counting-hemocytometer): Turns Neubauer grid counts into cells/mL with dilution factor, total-count option, and 20–100 cells/square density advice. Educational use only. - [Cell Density Unit Converter (cells/mL↔cells/µL↔10⁶/mL↔10¹²/L)](https://elysiatools.com/en/tools/cell-density-unit-converter): Convert cell density across cells/L, cells/mL, cells/µL, 10³/µL, 10⁶/mL, 10⁹/L and 10¹²/L for cell culture and hematology reports. - [Cell Doubling Time Calculator (t_d = ln2·t/ln(Nₜ/N₀))](https://elysiatools.com/en/tools/cell-doubling-time): Doubling time, doublings, and specific growth rate from two exponential-phase cell counts, in h/min/day. Educational use only. - [Trypan Blue Cell Viability Calculator](https://elysiatools.com/en/tools/cell-viability-trypan-blue): Viability % and live/dead/total cells per mL from trypan blue exclusion counts, with culture-health interpretation. Educational use only. ## Samples - [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion - [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion - [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion - [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion ## Related content - [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows. - [Image Format Conversion and Animated Export Tools](https://elysiatools.com/en/hubs/image-convert): Compare image format converters for JPG, PNG, GIF, AVIF, WebP, TIFF, ICO, base64, and animation-friendly exports in one hub. - [JSON Interchange and Format Translation Tools](https://elysiatools.com/en/hubs/json-convert): Compare JSON conversion tools for CSV, YAML, TOML, GraphQL, XML, Markdown, Excel, BSON, EDN, and related structured formats in one hub. - [Color Space Conversion Tools for Web and Print](https://elysiatools.com/en/hubs/design-convert): Curated tools for web-to-print color space conversion in one hub.