Crossing Over Calculator
About the Crossing Over Calculator
The Crossing Over Calculator is a scientifically validated, peer-reviewed tool that instantly determines recombination frequency and genetic map distance (in centiMorgans) from testcross or dihybrid cross progeny counts. It implements the maximum likelihood estimator and both the Kosambi and Haldane mapping functions — the exact standards used in professional genetic mapping software worldwide. Learn more at Crossing Over. Proudly supported by Agri Care Hub.
Why Crossing Over Is Fundamental in Genetics
Crossing over during meiosis I is the physical mechanism that generates genetic recombination, creating new allele combinations and enabling gene mapping. The Crossing Over Calculator converts raw offspring counts into precise recombination frequencies and centiMorgan distances — essential for constructing genetic linkage maps, QTL analysis, and marker-assisted breeding in plants, animals, and humans.
How to Use the Calculator
- Enter the number of parental (non-crossover) and crossover (recombinant) offspring
- Total offspring is automatically calculated unless you override it
- Choose Kosambi mapping for real-world interference correction (recommended for most organisms)
- Click “Calculate Recombination & Map Distance”
Scientific Formulas Used
Recombination frequency (r) = Crossover offspring / Total offspring
Haldane (no interference): d = −50 × ln(1 − 2r)
Kosambi (with interference): d = 25 × ln((1 + 2r) / (1 − 2r))
Applications
- Construction of high-resolution genetic maps
- QTL and association mapping validation
- Marker-assisted selection in crop and livestock breeding
- Teaching meiosis, recombination, and classical genetics
Conclusion
The Crossing Over Calculator delivers publication-quality genetic distances in seconds — completely free and fully compliant with gold-standard mapping methodology.
Powered by Agri Care Hub | Scientific reference: Crossing Over