Rings come in all different shapes, sizes and materials. Gold, like silver, can become relatively malleable under high heat. For this reason, it's an easier element to mold and shape as jewelry. If you need to resize a gold ring to make it larger, a jeweler will need to add on more material. Although this may cost more money, it can be seamlessly done by a professional.
Determine your actual ring size. It's important to have your finger professionally sized (as opposed to guessing) to avoid the same mistake in the future. Your size can be taken by any jeweler, regardless of whether or not they size rings. There is a measurement tool that can help you find the right fit.
Locate two or three different jewelers in your area that offer resizing options and compare prices. Jewelers charge various prices for their services so it doesn't hurt to shop around to find the best deal.
Verify that your ring is made 100 percent out of gold. If your ring contains other elements, the jeweler will not be able to seamlessly size it while welding on new gold. Attempting to size a ring incorrectly with another element may do permanent damage to the jewelry.