Biology
Trihybrid Cross Calculator
Predict offspring ratios for a three-gene cross, assuming independent assortment of all three genes.
Your inputs
Change any value to update the result instantly.
All-dominant phenotype probability
42.19 %
Genotype AaBbCc
12.5 %
Genotype AABbCc
6.25 %
Genotype AaBBCc
6.25 %
Genotype AaBbCC
6.25 %
Genotype AaBbcc
6.25 %
Each box of the Punnett square is equally likely; percentages are expected proportions across many offspring, not a guarantee for any single child. Assumes complete dominance and independent assortment of the genes.
What this calculator does
Predicts offspring ratios for a three-gene Mendelian cross with independent assortment.
What your result means
For AaBbCc × AaBbCc the phenotype split is 27:9:9:9:3:3:3:1 across the eight combinations.
Formula and working
8 gamete types per parent combine in an 8 × 8 square (64 outcomes); AaBbCc × AaBbCc gives 27:9:9:9:3:3:3:1 phenotypes
- 1
Collect the inputs
Parent 1 — gene A = 1; Parent 1 — gene B = 1; Parent 1 — gene C = 1; Parent 2 — gene A = 1; Parent 2 — gene B = 1; Parent 2 — gene C = 1
- 2
Apply the formula
8 gamete types per parent combine in an 8 × 8 square (64 outcomes); AaBbCc × AaBbCc gives 27:9:9:9:3:3:3:1 phenotypes
- 3
Result
All-dominant phenotype probability = 42.19 %
Frequently asked questions
Symbols and assumptions
- A/a, B/b, C/c
- Alleles of the three genes
- • All three genes assort independently.
- • Complete dominance at every locus.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • The 64-cell square is enumerated exactly; linkage, epistasis and environmental effects are not modelled.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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