This is a great tool for figuring the differences in sizes. Do you want to make a block or quilt 1/3 larger? Do you need to blow up or reduce the size of a pattern and you need to know the proportional difference to use on the copy machine? This is the tool for you!
Line up the measurement of your design on the inner ring and the new size measurement will display on the outside ring. The percentage of increase or reduction appears in the window opening. Measurements are shown in inches and percents.