To save the most money on your electric bills replace your bulbs with the lowest wattage for the desired lumens brightness.
9 watt led brightness.
The luminous intensity on.
While that works for incandescent bulbs although even then it is an imprecise way of measuring brightness with the development of low energy led light bulbs the wattage alone will not necessarily indicate how bright a bulb is.
The assumption is that a 100 watt light bulb for example is naturally going to be brighter than a 40 watt bulb.
The lumens scale indicates the brightness of a bulb and should be used when selecting your new led.
Led luminous intensity luminous intensity is another term for the brightness but it is related to the solid angle the luminous flux in lumens can only be used to measure the total light emitted by the lamp.
This means it s useless to use watts to determine brightness.
While the math for the cfl bulbs is simple the led bulbs are even more energy efficient and durable than compact fluorescent light bulbs.
Leds are designed to use less energy and naturally have a lower watt rating.
Led lamp 70 watt metal halide 30 watt led 100 watt metal halide 40 50 watt led 150 watt metal halide 60 70 watt led 175 watt metal halide 80 90 watt led 70 watt high pressure sodium 40 watt led 100 watt high.
For example you can have the same brightness from an old 60 w incandescent which has since been phased out from a halogen using 42 w cfl using about 13 w or an led using just 10 w.
Lumens are the new unit of measurement for brightness in light bulbs.
For example a correct replacement for a 60w incandescent bulb would be a 15 watt cfl bulb 60 1 4 15.
To choose a replacement bulb with the same brightness as your old one take it with you to the shop and match it up.
A light bulb that produces 800 lumens will produce the same brightness no matter if it is an led cfl or traditional incandescent bulb.
In fact a 60 watt led just may blind you.
Lumen output find your led bulbs here.
Watts to lumens energy output to brightness produced here is a breakdown of traditional watt light bulbs and the amount of light they produce in lumens.