The trend is to larger bathtubs; deeper tubs, tubs with curved sides. Bathrooms are trending to be more glamorous spaces and decor elements we used to regard as high-end are now more reasonably priced and the DIY'er can have a luxurious bathroom with the addition of a few elements. Curved bathtub shower curtain rods are available in many colors, finishes and sizes. The size of the shower curtain they require will vary.
Standard Curtain Sizes
Bathtub shower curtains are usually 70 inches wide by 72 inches long, which is a size that will fit a standard 60-inch tub curtain rod. Curved rods that are to be installed on a 60-inch tub do not require a larger curtain.
Installation of a Curved Rod
Extra care should be taken when deciding the installation height of the curved rod to ensure that the curtain will stay inside the bathtub, preventing water leakage.
Oversized Tubs and Rooms
Oversized tubs or rooms with higher-than-usual ceilings may require a longer tub rod than standard. Longer and wider curtains would then be required; the retailer of the tub should be able to supply sources for specialty curtains.
Alternative Curtains for Larger Tubs
Rather than purchase a large, or custom, curtain, consider using two-regular sized curtains in the same pattern. When hanging them, overlap the two curtains for two or three hooks at the center where they meet.