Get an over size tee (mine's 5x).

Up close on my fabric.

Fold over

place your tank top on top of the over size tee and line it up with the outside fold

Measure down 9"inches from bottom seam and mark. start from their to cut up. trace your top to make a tank dress)starting from the bottom.

Just like this pattern is cut out into a tank dress

tank dress

cut out neck piece.

Now sew from the side seams starting near the arm part. then after sewing turn inside out...

.... and VOILA !!!!!!