American dollar bills are rectangular in shape, with their width being larger than their height. If you have an oddly shaped gift card or short wallet, you may want to fold a dollar bill so that it measures a perfect square. Figure out the math on the dimensions of the dollar bill and you'll be able to fold it into a square that fits into any smaller place you desire.
Measure the height of the dollar bill. Unless it is cut crookedly, your dollar bill will be 2 5/8 inches tall. This will be the width and height of the finished square.
Measure the width of the dollar bill. A normal American dollar measures 6 1/8 inches wide.
Subtract the height from the width to find out how much width you need to remove to create a square. You will come up with 3 4/8 or 3.5 inches.
Divide the amount you need to subtract, 3.5 inches, by 2. This will give you the exact amount you need to remove on either side of the bill. This amount is 1.75 inches.
Measure from the right edge of the bill in toward the center 1.75 inches. Fold the right edge of the bill under at this point. Measure from the left edge of the bill toward the center 1.75 inches. Fold the left edge of the bill under at this point. The remaining dollar showing on top will be an exact square measuring 2 5/8 inches on each side.