How much is a lumen measured in?

Question

How much is a lumen measured in? eg. when a light bulb says 15,000 lumens, is that per foot or metre or what?

Answer 1

A lumen is the amount of light EMITTED from a light source/lamp, it has nothing to do with feet or meters. The amount of light reaching an object is measured in lux, but the relationship is far to difficult to explain on here! A globe shaped lamp with 1500 lumen output will emit light in almost all directions, whereas a 1500 lumen narrow beam reflector spotlamp will concentrate all the light on one point and therefore appear brighter.

Answer 2

lumens are a measure.

like  feet.  or pounds.

what's worse is, i don't know alternate units, like inches or kilograms.

it's just the amount of light.

you can't even say it's  X  amount  of something because it takes into account how your eye perceives the light.