What do I need to enter?

Parent 1 genotype, Parent 2 genotype. Optional fields can be left blank.

Punnett Square Calculator

Cross two parents for one or two genes and see the Punnett square with genotype and phenotype ratios.

Phenotype ratio

9 : 3 : 3 : 1

Genotype ratio: 1 AABB : 2 AABb : 1 AAbb : 2 AaBB : 4 AaBb : 2 Aabb : 1 aaBB : 2 aaBb : 1 aabb
A_ B_ (dominant A, dominant B): 56.25% (9/16)
A_ bb (dominant A, recessive b): 18.75% (3/16)
aa B_ (recessive a, dominant B): 18.75% (3/16)
aa bb (recessive a, recessive b): 6.25% (1/16)

Assumes complete dominance and genes that sort independently (not linked).

Punnett square (rows: parent 1's gametes, columns: parent 2's)

Gametes from each parent
one allele of each gene
AB, Ab, aB, ab × AB, Ab, aB, ab = 16 boxes
Count each phenotype
A_ = AA or Aa, B_ = BB or Bb
9 A_ B_ : 3 A_ bb : 3 aa B_ : 1 aa bb = 9 : 3 : 3 : 1

Each parent passes one allele per gene; every gamete pairing is equally likely. Capital letters are dominant (complete dominance)

How does the punnett square calculator work?: Each parent passes one allele per gene; every gamete pairing is equally likely. Capital letters are dominant (complete dominance).
What do I need to enter?: Parent 1 genotype, Parent 2 genotype. Optional fields can be left blank.