Question

What is the ratio of heterozygous offspring to total offspring in the punnett square

Answer 1

What are the genotypes of the parents?  if the parents are homozygous recessive, and homozygous dominant( like TT and tt)
it would be:
  T    T
t[Tt][Tt]
t[Tt][Tt]  Which would make heterozygous(Tt)  100%

HOWEVER,  if BOTH parents are homozygous dominant, or homozygous recessive(TT, or tt)

like so
   T   T
T[TT][TT]
T[TT][TT]  none would be heterozygous.

if both parents are heterozygous(Tt)(which I'm guessing is the case)
   T     t
T[TT][Tt]
t [Tt][tt]  Than your percentage would be 50%  (2:4 ratio) 

IF you could specify the genotype, that would be great.