Downloadable Light Bulb Diameter Measuring Tool

Light Bulb Diameter Tool
Download the diameter tool now
(109 KB PDF)

Deciding which replacement lamp you need can be a difficult task, particularly if you are trying to measure across the diameter of a bulb. We have put together a handy scale diagram for you to refer to.

Simply print out and cut along the required lines and compare to the lamp you have. Remember to ensure 'Page Scaling' is set to 'none' under the 'Page Handling' options in the print window.

The tool has measurements for the following fluorescent tubes, reflectors light bulbs and PAR lamps:

Fluorescent Tubes

T2, T4, T8, T10, T12

Reflector Light Bulbs

R39, R50, R64, R80, R95, AR111, R120, R125

PAR Lamps

P11, P16, P20, P25, P30, P36, P38, P46, P56, P64


Light Bulbs

Spend £18 For Free Delivery

(excludes long fluorescent tubes)

Delivery Information


if ordered by 12pm* (GMT)

Delivery Information