Find your led strip power consumption by entering your wattage, the hours a day your led strip runs and your electricity rate. Click Calculate and you get your cost per day, month and year along with the kWh it uses. Those same results also cover led strip electricity consumption.
Planning a lighting project and wondering what it will do to your power bill? LED strip power consumption is easier to predict than most people expect: multiply the watts per meter by the length, then by the hours you run it. This guide walks you through that math for your LED strip lights, from total wattage to a daily cost, so you can pick the right supply and keep your energy use low.
Every strip carries a rating in watts per meter, and that single figure sets the baseline for how much electricity your setup pulls from the wall. Keep that rating in mind whenever you compare LED strips, because the power consumption of LED strip lights scales almost linearly with length. An LED strip is a chain of small LED chips on a flexible circuit board, so the more chips you pack in and the harder you drive them, the higher the power draw. Everything else in this guide, from the supply you buy to the monthly bill you see, grows out of that rating and the length you install.
You only need four values to estimate energy consumption: the rated power in watts per meter, the LED strip length in meters, the hours of daily usage, and your electricity rate. The rating is printed on the reel, the datasheet or the product listing, and your rate is on your utility statement.
Anyone comparing LED strip wattage between brands should remember that the label shows the draw at full brightness and full voltage. Dimming, color choice and even the quality of your connections change what the LED strip really uses, which is why the later sections look at each of those factors one at a time.
A typical white strip lands somewhere between 4 and 15 watts per meter, while bright, dense or color-mixing strips can climb past 20 watts per meter. That is small next to a household appliance: a 5 meter reel at 13.2 watts per meter draws 66 watts, about the same as one old incandescent bulb. Because LED strip lights are rarely on around the clock, most home lighting installs add only a few dollars a month to the electric bill.
| Strip length | Total power at 13.2 W/m | Daily energy at 5 hours | Monthly electricity cost |
|---|---|---|---|
| 2 m | 26.4 W | 0.132 kWh | $0.65 |
| 5 m | 66 W | 0.330 kWh | $1.62 |
| 7.5 m | 99 W | 0.495 kWh | $2.44 |
| 10 m | 132 W | 0.660 kWh | $3.25 |
The monthly cost column assumes 30 days and an electricity rate of $0.164 per kWh. Swap in your own rate to see your local figure.
The first step is the total power consumption of the run. Multiply the rated watts per meter by the number of meters you plan to install:
$$P_{\text{total}} = P_{\text{per meter}} \times L$$
Here \(P_{\text{per meter}}\) is the rated power in watts per meter and \(L\) is the LED strip length in meters. If your LED strip is rated per foot instead, convert the length first so both values use the same unit. Cut-to-length reels work the same way, because the circuit board is simply divided into short segments.
Check whether the lighting listing quotes watts for a full 5 meter reel or watts per meter. Some listings quote the power rating of the whole reel, and mixing those up makes your estimate off by a factor of five.
Good wiring and a tidy installation keep losses low, and controllers and receivers draw a little power of their own, usually a watt or two, plus standby current when the lights are off. Include them if you want an exact total, though for a single strip they rarely change the answer.
Take a 24V white strip rated at 13.2 watts per meter, installed along a 7.5 meter kitchen soffit. It runs 5 hours a day, and the local electricity rate is $0.164 per kWh. The calculation goes in four steps:
A higher-density reel would shift the LED strip light power consumption upward in the same proportion. Over a full year of the same schedule, that is roughly 180.7 kWh and $29.63. The steps are easy to repeat in a spreadsheet or in any online LED power calculator once you know the rating.
Watts describe how fast an LED strip uses power at a given moment, while your utility bills you for energy over time. That unit is the kilowatt-hours figure, written kWh, and one kWh equals 1,000 watt-hours.
$$E_{\text{kWh}} = \frac{P_{\text{total}} \times t}{1000}$$
In this formula \(t\) is the time the lights are on, in hours. Multiply the result by the price per kWh and you get the electricity cost for that period.
Multiply your daily energy by the number of days in the month and then by the rate to see the monthly electricity bill. If you leave the LED strip on for ten hours, double the five-hour figures in the table above.
You will sometimes see claims that an LED strip "uses 12 watts per hour." A watt already means energy per unit of time, so say "12 watts" for the rate and "watt-hours" for the total after a given usage time.
The supply voltage does not change how many watts an LED strip is rated for, but it changes the current flowing through the copper. Current equals power divided by voltage, so the same 99 W strip behaves quite differently on each supply:
| Supply | Total power | Current |
|---|---|---|
| 12V strip | 99 W | 8.25 A |
| 24V strip | 99 W | 4.13 A |
| 48V strip | 99 W | 2.06 A |
Choosing a light strip on 24V instead of 12V also halves the current. Lower current means thinner wire, less heat in the connectors and a gentler fall in brightness along the run, which is why installers favor 24V for anything longer than a few meters.
Whether you use an LED light strip or a pixel strip, the longer the run, the more the copper traces resist the flow, and the far end of the LED strip gets less than the full supply. You see this as dimmer or warmer-looking light and sometimes flickering at the end of a reel. Voltage drop does not make an LED strip use more energy than its rating; it makes the LED strip you paid for deliver less light. Related: how much electricity does a table fan use.
Match the wire gauge to the current in your table above. A thicker wire cross-section keeps the loss in the supply cable small, and a heavier feed matters most when the supply sits far from the LED strip.
Feeding power at both ends or at several points, known as power injections, keeps the brightness even. Wiring each LED strip segment separately is cleaner, so segment the run so no single section carries more than the datasheet allows, and place a fuse on every feed to protect the wiring.
Once you know the total wattage, the next step is the power supply. It has to match the LED strip voltage exactly and should never run at 100 percent of its label, because constant full load shortens its life and invites overheating. A power reserve of 20 to 30 percent is the usual rule, and it protects the power supply as much as the LED strips themselves. Compare with how much energy does a nintendo switch ac adapter use.
$$P_{\text{supply}} \geq P_{\text{total}} \times 1.25$$
For the 99 W example, 99 × 1.25 = 123.75 W, so a 150 W, 24V unit such as a Mean Well LPV-150-24 is a comfortable fit. Choose the power supply last, after you have settled the length, voltage and dimming plan. The extra headroom also absorbs start-up surges and any accessories you add later.
Dry indoor lighting spots can use a slim switching power supply, while damp or outdoor installs need a sealed unit rated IP65 or IP67. Check the rating before buying, not after the first wet season.
An overload trips the protection circuit, flickers the lights or cooks the unit over time. If your LED strip has several segments, add the wattage of every segment before choosing, because a supply sized for one segment will not carry the whole install.
For lighting designers, dimming is the most direct way to cut energy consumption without removing a single LED. Most controllers use PWM dimming, which switches the LED strip on and off thousands of times a second; at 60 percent brightness the average draw falls close to 60 percent of the rating. For the example strip that is 59.4 W instead of 99 W, a monthly bill of about $1.46 instead of $2.44.
Dimmers and smart controllers for LED light strips also let you set a timer so the lights are off when nobody needs them. Keep in mind that the controller itself uses a small standby current, so a high-quality unit with low idle consumption is worth the price.
Strips are sold by the number of chips per meter, and the LED density is a big reason one reel is rated at 7 W/m and another at 20 W/m. More chips mean more light and more watts.
Lighting efficiency tells you how much light you get for the power you pay for. Luminous efficacy is measured in lm/W, or lumens per watt, and an LED strip that makes 1,300 lumens from 13 watts delivers 100 lm/W.
$$\text{Efficacy} = \frac{\text{Lumens}}{\text{Watts}}$$
Better energy efficiency shows up as lower electricity consumption for the same brightness. Higher efficacy means the same brightness at lower consumption, so comparing lumens per watt across two strips is a better test than comparing watts alone. Each LED chip is a semiconductor diode that converts electricity directly into light, which is why a good strip, with its energy efficiency measured in lumens per watt, wastes far less as heat than a filament.
To produce 1,000 lumens, an incandescent bulb at roughly 15 lm/W needs about 67 W, a fluorescent at 60 lm/W needs about 17 W and an LED strip at 100 lm/W needs about 10 W. Run each for 5 hours a day over 30 days: Compare with air fryer power consumption.
| Light source | Efficacy | Power for 1,000 lumens | Monthly energy | Monthly cost |
|---|---|---|---|---|
| Incandescent | 15 lm/W | 66.7 W | 10.0 kWh | $1.64 |
| Fluorescent | 60 lm/W | 16.7 W | 2.5 kWh | $0.41 |
| LED strip | 100 lm/W | 10 W | 1.5 kWh | $0.25 |
Those energy savings in everyday lighting are what make the format an eco-friendly choice compared with traditional lighting, and it is why efficiency gains matter most in rooms with long daily usage. A quality strip can also reach a lifespan of 50,000 hours, so you pay for fewer replacement bulbs on top of the lower kWh.
High ambient temperature lowers LED efficiency, so a hot strip needs more watts to deliver the same light and adds to your electricity consumption. Heat dissipation matters most for dense strips in closed cabinets or foam-lined coves. Mounting the LED strip in an aluminum channel pulls heat away from the board, which keeps the LED strip at its rated efficacy and its power draw close to the datasheet figure.
A commercial storefront lighting plan with 60 meters of strip at 14 W/m draws 840 W, so the supply layout, the circuit breaker size and the voltage choice all become design decisions rather than afterthoughts. In both cases, 24V or 48V keeps the current low and the wiring manageable.
You can reduce the monthly cost without giving up the look. The best energy-efficient setups apply several of these ideas at once. For comparison, see how many watts does a tube light use.
Before you buy a reel, turn the wattage estimate into a running-cost budget for the year, working backward from the rated power. A well-planned installation beats an improvised one because every extra meter of LED strips adds both purchase price and running cost. Walk through this checklist of LED strip lights for every lighting zone in your LED project:
A bargain light strip can pull more power than its listing suggests, so measuring the real draw with a plug-in energy meter during a test run is the simplest reality check before final installation.
A few repeat offenders show up in almost every project. Skipping the reserve and running the supply flat out is the first. Mixing up the LED strip and supply voltage is the second, and it can damage the LED strip. Overlooking the voltage drop on a long 12V run is the third, and it leads to uneven brightness and extra supply stress. A fourth is trusting a vague listing: an LED light strip sold without a clear watts-per-meter figure makes electricity consumption impossible to predict. Finally, leaving lights on all day by habit adds more to the bill than any technical detail.