Things You'll Need
Large square cardboard box
Successful balloon arches, arrangements and bouquets depend on uniformed balloon sizes so that the final shape is even. A balloon sizer keeps the balloon blown up to the same size every time. Professional party planners use balloon sizers to decorate parties in this way. Even if you decide to display balloons individually, keeping the balloons equal in size can help tie the party decor together with consistency. Make your own homemade balloon sizer for use at home.
Tape the flaps of a large, square cardboard box shut with masking tape.
Adjust a drawing compass by spreading the stationary end and the drawing end as far away from each other as half of the width you want each balloon to be.
Place the stationary end of the compass onto the center of one side of the box and pivot the compass to draw a circle with the drawing end.
Cut out the circle with a utility knife to leave a hole, which is the size that you want your balloons to be.
Blow up a balloon larger than you want and let a bit of air out slowly until the balloon is just small enough to pass through the circle. Tie it off at this point.
Cut several different sized circles into the box to make different sets of balloon sizes.