The power consumption of an LED is equal to the wattage of the LED multiplied by the number of hours it is used. To be more specific, this metric is cumulative power consumption, as it factors in the amount of time used.

Two light bulbs, incandescent and LED.

Light bulb and glowing LED bulb on black.
Image credit: Stoycho Stoychev / Bigstock.com

Before we continue, it’s helpful to get an idea of what an LED actually is. An LED is a light-emitting diode. These tiny electronic chips glow when an electric current is passed through them. LEDs operate on DC current internally, and with low voltages (most of them are in the 3.3 Volt to 3.7 Volt range).

Disclaimer: All the information provided herein is not for budgetary purposes. It’s purely for the sake of gaining a better idea of LED power consumption. Use it at your own risk. 

However, they have conversion circuitry to take care of that, so you won’t have to worry about voltage or current ratings. These tiny chips are then incorporated into LED light bulbs in large quantities (for example: 20 LEDs in a bulb) with LED driver circuitry so that you can simply screw your LED bulb into a standard E27 light bulb receptacle in place of your old CFL.

The power consumption of LEDs used in LED light bulbs is usually in the 0.1-Watt to 1-Watt range, but there are many models outside that range that consume far more or less (for example: I used 3.6-Watt LEDs to build my solar lantern, an unusual practice).

LED Power Consumption (In the context of 120-Volt light bulbs)

The power usage of LED bulbs ranges from 1 Watts to hundreds of Watts (at this brightness, they’re not necessarily bulbs, but large lamps), depending on the application, so i’ll break it down by the required brightness. The power consumption of 800-lumen (60-Watt equivalent) LEDs ranges from 9.6 to 7.1 Watts for the latest models on the market. There are significantly worse models on the market that will consume far more than that.

All I can say for those is: Don’t buy them. The 9.6 to 7.1 Watt models are common enough and obtainable (also a few dollars per bulb), they’re everywhere you turn.

If you use it for 6-hours per day, and 30 days per month, an 8-Watt LED’s power consumption will be  1,440 Wh per month (1.44 kWh per month or 17.28 kWh per year). This works out to:

Currency: USD. The electricity rates below don’t necessarily match yours, they are based on rough averages obtained for the regions mentioned. They are also subject to change without notice.

  • $0.172 per month at an electricity rate of $0.12 USD/kWh (United States).
  • $0.36 per month at an electricity rate of $0.25/kWh (this rate is close to that of many European countries, among others).
  • $0.418 per month at an electricity rate of $0.29/kWh (Australia).
  • $0.65 per month at an electricity rate of $0.45/kwh.

Why 800 lumens? 800-lumen bulbs are typically bright enough to light rooms in the 100-150 square-foot range depending on the fixture used. If you want immensely-bright lighting, a 1200 lumen LED would be perfect. As I said, this is only the case for certain fixtures (and definitely not the case for recessed lighting fixtures, which reduce the efficacy of the bulbs dramatically by absorbing too much of the light).

If you use several 60w equivalent bulbs per room, then the following would be more relevant (5 bulbs per room assumed for this scenario and the same 6-hour/day usage).

Power consumption of LEDs per room (assuming the above scenario):

7.2 kWh, which works out to:

  • $0.86 per month at an electricity rate of $0.12/kWh (United States). $6.02/month for 7 rooms.
  • $1.80 per month at an electricity rate of $0.25/kWh (close to that of EU countries). $12.60/month for 7 rooms.
  • $2.09 per month at an electricity rate of $0.29/kWh (Australia). $14.63/month for 7 rooms.
  • $3.24 per month at an electricity rate of $0.45/kWh. $22.68/month for 7 rooms.

Incandescent light bulbs consume approximately 10 times as much power (although sometimes less). Imagine how much it would cost if you went back to using them! (multiply the figures above by 10).

Light Bulb Efficiency

The efficiency of LEDs and other light sources is measured in lumens per Watt, and this can often be found on the packaging of LED light bulbs. On the packaging, it is usually on the back written something like this: ’88 lm/W). That’s 88 lumens of light per Watt of power the LED draws. You would multiply the lm/W rating by the wattage to get the brightness.

Many light bulbs (usually incandescent and some fluorescent bulbs) don’t have the efficiency rating printed on them, but you can easily calculate their efficiency rating if the brightness (in lumens) is written on the packaging.

For example: 800 lumens / 8 Watts = 100 lumens per Watt.

The efficiency of modern LEDs is almost always over 80 lumens/Watt and is starting to break through the 200 lumen/Watt threshold (these models aren’t very common). Realistically, most of what you’ll see is in the 86-100 lumen/Watt range. 90-Watt isn’t hard to find, so get those if you can (always aim for the best!).