So What's (not 'Watts') a Lumen?

Purchasing lightbulbs has become slightly more confusing with the advent of energy saving LED bulbs. They have their merits in the sense that they last longer and they keep more money in our pockets, but the problem arises when one goes to purchase one of these gems of the cost-effective lighting revolution.

Previously lightbulbs were sold by a measurement of how much energy they consumed, i.e. Watts (W). Nowadays, looking on an LED lightbulb box one does not see the familiar W symbol for Watts, instead one sees Lumens (lm). So what exactly is a Lumen and how does it compare with a Watt?

In scientific terms a Lumen is an International System of Unit (or SI unit) used to represent the amount of observable light produced from a source, known as luminous flux. Simply put, a Lumen is just another measure in the same way that Watts are, except this time instead of measuring how much energy a lightbulb consumes it is a measure of how much light a lightbulb produces. Even more simply put, a Lumen is a measure of brightness. Vis a Vis, the more Lumens a lightbulb has the brighter the bulb will be and the more light it will distribute.

The next irksome issue that comes into play is deciding on how many Lumens will provide the requisite amount of brightness. There are some lightbulb manufacturers that will place Watts-to-Lumen conversions on the side of their product packages to help you in your purchases, however this is not guaranteed and therefore there is a simple rule of thumb that you can use to ensure you make an informed decision. LED lights generally work on a 14lm:1W ratio and then rounding to the nearest available bulb luminosity. For example an average household 60W bulb working on the 14:1 ratio will round down to a 800lm LED bulb, while a 75W bulb will round up to a 1100lm bulb.

So there you have it. Problem solved and mystery unveiled; Lumen is no longer a linguistic enigma limited to those learned in “electrician-ese”. Happy lightbulb hunting.