Width/wɪdθ/ Definition 1 of 3Pro Tip 1/3Physical Distance Focus on the physical space between sides, not the object's height or length. Ensure the width between the shelves fits your books. Pro Tip 2/3Measurement Unit Width is usually measured in units like meters, inches, or pixels. The width of the window should be measured in inches. Pro Tip 3/3Across Not Along Width is the distance across, not along. It's horizontal, not vertical. Measure the width of the garden, not the path that runs through it.