One of the most important things to do when you are planning to change your watch band is to measure the existing band (if possible) and find out the width and length. Without those two measurements, you will not be able to ensure that you have the right size watch band for your watch case. Use this guide from Esslinger.com to help you successfully measure a metal watch band.
Before you can measure the watch band, you must first remove the old band from the watch case. You can learn How to Remove a Metal Watch Band here.
Once the old watch band has been removed, the first thing to do is determine the width of the watch band. Do not try to measure the end of your metal watch band like you would with a leather band: since some metal bands have expandable ends, this measurement can be misleading for width. You can measure for the width with either a ruler or a digital gauge, though the digital gauge will give you the most accurate results.
Hold the watch case in your hand so that the lugs are facing outward. Then take your digital gauge and place the backward opening upper jaws in between the watch case lugs. Open the gauge’s jaws until they fit snugly against the inside of the watch lugs. Record the millimeter measurement listed on the gauge’s display. If the measurement is not a whole number, round up if the decimal is five or above, and round down if the decimal is less than five.
Using the ruler, take your watch case and line the inside of the watch lug up with the zero marker on the metric side of the ruler as most watch band widths are given in millimeters. When the watch lug is aligned, read the measurement on the ruler where the inside of the second lug lines up with the lugs. Estimate smaller if the edge is between two millimeter marks on the watch band.
Now that you know how wide the watch band is, you can measure for the length of the watch band. Start by making sure your watch clasp is closed to give you the most accurate measurement.
Then align your watch band with your ruler. Make sure that the zero marker meets the end of the watch band or the pointed tips of the end cap if the watch band has an end cap. Read the measurement where the other end of the watch band ends on the ruler. This is the length of your watch band.
Once you have the length measurement, you can easily order a replacement band that is the perfect size for your watch. If you need help changing your watch band or placing the new watch band on you watch case, check out this article.