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Not sure how to measure the diameter of a lamp post globe or street lamp so you can buy a replacement? We can take the mystery out of calculating your lamp post diameter and show you how to order replacement light globes.

After 15 years in business, the most common inquiries we receive from Lamp Post Globes customers are about how to measure a replacement lamp globe.

Figuring out how to determine the size of a lamp post globe for your needs can be easily determined with a ruler or tape measure.

How To Determine The Size Of A Lamp Post Globe

There are three basic measurements you need to measure light globes: the height, the width and the fitter size. Follow these steps to determine the proper sizes:

  • Place the globe you are replacing on a secure surface with the open side down.
  • Using a ruler or a measuring tape, measure the height from the globe top to the base of the fitter.
  • Determine the width by wrapping the measuring tape around the belly or widest area of the globe, or by otherwise measuring its widest portion.

To determine the diameter of a round globe, place a ruler inside the globe and measure from the top of the globe to the bottom of the flange. This will give you the lamp post diameter. The flange, or 'neck,' is the external lip or rim which protrudes from the base of the globe, with screws to hold the globe in place.

Measurements of a circle

If you have a neckless globe, it is important to note that the vertical diameter is less than the horizontal diameter. This is because the cut at the bottom removes some of the diameter of the lamp post. This will have an impact if you need a certain amount of clearance to accommodate the height of the bulb inside. The diameters of our globes come in even-numbered increments (eg. 10 inch, 12 inch, 14 inch, etc.)

How To Measure Light Globes Which Are Not Perfectly Round

Knowing how to correctly measure lamp globes that are acorn-shaped or non-round is simple. Measure the globe at its widest part to determine the circumference. Then, divide the circumference by pi or 3.14 to get the globe's lamp post diameter.

How To Correctly Measure Light Globes' Flange Sizes

Globe flange sizes

The next measurement you need is the size of the flange or opening at the bottom of the globe. The flange will typically have three or four grooves on the bottom which allow it to sit into the fitter. Generally, flange sizes are determined by the outside edge of the flange. Place a ruler across the opening of the globe at its widest. The outside diameter of the flange will be slightly less than the size of the fitter. For instance, a 12-inch globe with a flange diameter of 3.91 inches is made to fit a 4-inch fitter.

Globe fitter diameter

How To Measure Light Globes' Fitters

If your globe is broken or missing, you may only be able to determine its estimated size. In these situations, the most important piece of information is the inside diameter of the fitter. Simply place a ruler across the fitter at the widest part and measure the inside diameter of the fitter.

Order Replacement Lamp Post Globes Today

Even if it isn't damaged or worn out, it may be a good time to revive and restore the look of your lamp post globe. Once you've determined your lamp post diameter, browse our huge selection of everything from traditional round replacement globes to rustic-style acorn globes.

If you have any questions or concerns about how to order replacement lamp globes for your application, please call 386-264-2615 or email us at [email protected].


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