**There are a total of 79 squares.**

Lets assume smallest square side length is 0.5 cms, then

Number of squares with side 0.5 cms: 30

Number of squares with side 1 cms: 16+11

Number of squares with side 1.5 cms: 2 + 3 + 2

Number of squares with side 2 cms: 9 + 1

Number of squares with side 2.5 cms: 0

Number of squares with side 3 cms: 4

Number of squares with side 3.5 cms: 0

Number of squares with side 4 cms: 1

Total: 79