How long could that coat of paint last? Five to 10 years for exterior paint and five to 15 for interior paint, according to Better Homes & Gardens.

It depends on many factors, including sun exposure and weather outside, and wear and tear inside. The quality of paint matters, too.

Your clients may not want to wait for the cracks and fading—and greater costs—that come with an aging paint job. They may want to try a new color well before they have to repaint. But they also may be able to put their previously used paint to work somewhere new. Leftover paint, properly resealed and stored, can last many years, according to