The first few days with a new wellness device are usually all excitement, then one evening a quieter thought shows up: I'm plugging this in every day, how much is that actually adding to the bill? If your household is already bracing for a heavier electricity statement from summer cooling or winter heating, it's a completely reasonable thing to want to check before you commit to a daily habit.
Here's the short version up front: an NIR LED device doesn't consume power the way a hair dryer or an electric heating blanket does — the underlying electrical structure is different. But short version aside, it's worth running the actual numbers rather than assuming it away. This guide walks through the real rated power draw of the CIRIUS LED Pro (108W) and LED Compact (24W) and calculates, step by step, exactly what 15 or 30 minutes a day costs per month. If you're still deciding between models, the CIRIUS Product Selection Guide covers the spec differences in more depth. Every number and formula used below is laid out in order so you can re-run the math with your own usage pattern.
How Much Power Does an NIR LED Device Actually Draw
Before any cost calculation makes sense, you need the device's rated power consumption in watts (W). That single number is the starting point for everything that follows.
LED Pro vs. LED Compact: a real difference in draw
The CIRIUS LED Pro is a panel-style dual-wavelength device combining 660nm red light and 850nm near-infrared across 120 LED chips arranged over a 30cm × 20cm irradiation surface, rated at 108W. The handheld LED Compact, by contrast, uses a single 850nm wavelength across 36 LEDs and draws only 24W. Two devices from the same product family, both technically NIR LED devices, and the power draw differs by more than 4x depending on panel size and LED count — that's the first thing worth internalizing before you do any math.
Why LEDs draw so much less than heat-based appliances
Electric blankets, hair dryers, and heating pads generate warmth by pushing current through a resistive element, and that process typically demands power ratings in the hundreds of watts to several kilowatts. LEDs work differently: they emit light of a specific wavelength directly at the semiconductor junction, with far less energy lost per unit of output compared to resistive heating. The LED Pro's 108W rating is less than a tenth of a typical household hair dryer's rating (1,200–1,800W). That gap is exactly what drives the cost difference calculated later in this guide.
Battery-powered models are calculated differently
Handheld models like the LED Compact, or devices like a knee massager, run wirelessly off an internal battery rather than staying plugged into an outlet during use. For these, the technically precise electricity cost is based on what the charger actually draws from the wall, not the operating time of the device itself. That said, the rated power figure still gives a useful reference for how much power the device draws at any given instant, so for simplicity this guide uses rated power × usage time as a common formula across both device types. For charging habits and battery longevity, see the CIRIUS Battery and Charging Care Guide.
The Electricity Cost Formula, Worked Through Step by Step
The math here is simpler than it looks. One formula, and you can estimate the monthly cost of any household appliance.
The base formula
Energy used (kWh) = Rated power (W) × usage time (h) ÷ 1000
Multiply that by your local residential electricity rate and you get an approximate cost. As a reference point, Korea Electric Power Corporation's (KEPCO) residential low-voltage rate structure is tiered by monthly usage: roughly ₩120.0/kWh for the first 200 kWh, ₩214.6/kWh for 201–400 kWh, and ₩307.3/kWh above 400 kWh (2024 figures). A basic monthly charge, VAT, and a power-industry infrastructure fund surcharge are added on top of this, so your actual bill line item will differ somewhat from the raw energy-rate math below — worth keeping in mind before comparing this guide's numbers to your statement.
Working the LED Pro numbers
- Assume 15 minutes (0.25h) of daily use: 108W × 0.25h ÷ 1000 = 0.027kWh
- Over 30 days: 0.027kWh × 30 = 0.81kWh
- Converted to cost: 0.81kWh × ₩120.0 (tier 1 rate) ≈ ₩97; the same usage at the tier 3 rate comes to 0.81kWh × ₩307.3 ≈ ₩249
Run 15 minutes a day for an entire month and the pure energy charge lands somewhere around ₩97–249 — less than the price of a single cup of coffee.
Three steps to calculate your own usage
If your actual pattern doesn't match the example above, work through it in this order.
- Step 1: Find the rated power (W) of your device from the spec sheet or the label on the unit itself
- Step 2: Convert your average daily usage time to hours (minutes ÷ 60) and plug it into the formula above to get daily energy use (kWh)
- Step 3: Multiply the daily figure by 30 to get monthly energy use, then apply the tier rate your household currently falls into (check your most recent bill for which usage tier applies)
What this produces is the pure incremental cost of running that one device on its own. It's worth remembering that once your household's total usage — this device plus everything else — crosses into a higher tier, the marginal rate applied goes up accordingly.
Rated power isn't always the same as actual draw
The rated power on a spec sheet is generally the maximum output figure the device is capable of, and actual average draw during real use often measures lower. The LED Pro may be rated at 108W, but if the device modulates output during certain phases of a session or sits in a timer-idle state, the measured average can come in under that number. If you want the exact figure, the most reliable method is a low-cost smart plug with power monitoring (typically $10–20) connected between the outlet and the device — it will show real-time draw and cumulative kWh as you actually use it. Treat the numbers in this guide as a conservative upper bound based on the rated spec, not a precise measurement of your specific unit.
Monthly Cost by Daily Usage Time
The table below is a simple calculation based on rated power and daily usage time, shown as a range between the tier-1 rate (₩120.0/kWh) and the tier-3 rate (₩307.3/kWh). VAT and the basic monthly charge are excluded — this is pure energy-rate cost only.
| Device | Daily usage | Daily energy use | Monthly energy use (30 days) | Estimated monthly energy cost |
|---|---|---|---|---|
| LED Compact (24W) | 15 min | 6Wh | 0.18kWh | ≈ ₩22–55 |
| LED Compact (24W) | 30 min | 12Wh | 0.36kWh | ≈ ₩43–111 |
| LED Pro (108W) | 15 min | 27Wh | 0.81kWh | ≈ ₩97–249 |
| LED Pro (108W) | 30 min (15 min AM + PM) | 54Wh | 1.62kWh | ≈ ₩194–498 |
| LED Pro (108W) | 40 min (20 min AM + PM) | 72Wh | 2.16kWh | ≈ ₩259–664 |
Even the heaviest scenario in the table — LED Pro, morning and evening at 20 minutes each — doesn't cross ₩700 a month in pure energy cost. That's daily, uninterrupted use for a month, coming in around the price of a couple of coffees. One caveat: this table shows the incremental cost of running this one device in isolation. If your household is already sitting in tier 3 because of other appliances, expect a number closer to the higher end of each range.
Standby Power and Charging Losses You Might Be Missing
Everything calculated so far assumes the device is only drawing power while actively running. Leave a charger plugged into the wall, or leave the cable connected after charging finishes, and a small amount of power gets added that none of the math above accounts for.
Standby power is a real, measured phenomenon
Researcher Alan Meier at Lawrence Berkeley National Laboratory (LBNL) led a body of work starting in the late 1990s measuring what's often called phantom load or standby power — the small but continuous draw that chargers and small-appliance adapters pull simply from being plugged in, even after charging or operation has stopped. A single small switching adapter typically draws somewhere in the 0.1–2W range on its own, which isn't much, but the core finding of that research was that the effect stops being negligible once you account for every charger and adapter plugged in around a house simultaneously.
Standby power is managed on the regulatory side too
The Korea Energy Agency (KEA) has run a standby power reduction program (e-Standby Korea) that measures the standby draw of appliances sold domestically and publishes an annual list of low-standby-power products, using 1W or below as the recommended benchmark for small adapter-type devices. Genuine KC-certified CIRIUS adapters are generally designed to meet this benchmark, though the exact standby figure varies by individual charger model and isn't something most users can easily measure at home. For reference, the IEC 62301 standard defines a consistent test procedure for measuring standby power, and it's the basis many manufacturers use when publishing their own standby figures.
Charging losses are small but real too
When a battery charges, not all of the power drawn from the outlet ends up stored in the cell — some is lost as heat. Typical lithium-ion charging efficiency runs 85–95%, which means actual wall-outlet draw is realistically 5–15% higher than a battery-capacity-based calculation would suggest. That gap only adds a few dozen won on top of the ₩100–700 monthly figures calculated earlier, so it doesn't change the overall conclusion (electricity cost for NIR LED devices is minor). Unplugging the cable when you're not charging removes most of this loss on its own.
How this differs from the auto-cutoff circuit
One point worth clarifying: as covered in the CIRIUS Battery and Charging Care Guide, the battery management system (BMS) automatically cutting charge current once the battery is full is a different thing from standby power. The BMS blocks current flow into the cell to protect it from damage; standby power is separately drawn by the adapter's own conversion circuitry just to stay connected and ready. In other words, charging stopping automatically at full doesn't put the adapter in exactly the same power state as unplugging it — that residual gap is the 0.1–2W standby draw described above.
How It Compares to Other Household Appliances
Numbers in isolation don't always land, so here's the LED devices placed side by side with common household appliances. Figures below are estimated monthly cost based on typical rated power and a representative usage pattern for each.
| Appliance | Rated power | Typical daily use | Monthly energy use | Estimated monthly energy cost |
|---|---|---|---|---|
| Electric heating blanket (single, nightly) | ≈ 100W | 8 hours overnight | ≈ 24kWh | ≈ ₩2,880–7,375 |
| Induction cooktop (single burner) | ≈ 2,000W | 20 min/day | ≈ 20kWh | ≈ ₩2,400–6,146 |
| Hair dryer | ≈ 1,200W | 10 min/day | ≈ 6kWh | ≈ ₩720–1,844 |
| Refrigerator (200L class, always on) | avg ≈ 40–50W | 24 hours | ≈ 30kWh | ≈ ₩3,600–9,219 |
| CIRIUS LED Pro | 108W | 15 min/day | 0.81kWh | ≈ ₩97–249 |
| CIRIUS LED Compact | 24W | 15 min/day | 0.18kWh | ≈ ₩22–55 |
Lined up against appliances that run for meaningful stretches of time every day — an electric blanket, an induction cooktop, even a refrigerator's constant cycling — the CIRIUS devices sit in an entirely different order of magnitude. That comes down to the fact that an NIR LED was never built to generate heat in the first place; it's a light source engineered to emit a specific wavelength efficiently. If cost has been the thing holding you back from using the device more, this comparison should make the decision easier. If you're setting up more than one device in a dedicated space, the CIRIUS Home Wellness Setup Guide is worth a look too.
A different way to think about the number
If ₩100–700 a month still doesn't feel concrete, try it this way: a month of using the LED Pro morning and evening, every single day, costs less than a single canned coffee from a convenience store. On the flip side, a single habit — running an electric blanket every night through the winter — can generate roughly the same bill as running ten LED devices simultaneously. One caveat worth repeating: these table figures assume a specific usage pattern, and actual bills will vary with seasonal fuel-cost adjustments, household size, and local rate structures.
A Practical Checklist for Trimming the Bill
Given the math above, the NIR LED device itself is already a minor line item — but if you want to trim it further, these habits help.
- Unplug the charging cable or adapter from the wall once you're done, eliminating standby draw entirely
- For battery-powered models, avoid leaving them plugged in after they hit full charge — charge only what you need right before use (this also helps battery longevity)
- In months when other appliance usage is already pushing you toward tier 2 or 3, look at cutting back on higher-draw appliances (induction cooktop, electric blanket, hair dryer) before worrying about LED usage time
- If multiple chargers share a power strip, switch the whole strip off during hours nobody's charging anything
- Once a month, check your bill's total usage tier so you know which rate is actually being applied — it makes every future calculation more accurate
The honest takeaway here is that this checklist's real savings come from household-wide standby power and high-draw appliance habits, not from the LED device itself. The device is already consuming so little that cutting back your usage time to save money isn't really worth the trade-off — using it the way it's intended makes more sense.
What one user found with a smart plug
One CIRIUS Pro owner, curious enough about the electricity cost to check it directly, connected a power-monitoring smart plug between the outlet and the adapter and tracked cumulative usage over a month. Running the device for 20 minutes every evening, the smart plug logged about 1.1kWh over the month, which at the tier-2 rate they were on at the time (≈₩214.6/kWh) worked out to roughly ₩236. That came in somewhat higher than this guide's formula-based estimate (≈₩130–166 for the same pattern), most likely because the reading also captured idle time between sessions and the brief current spike at power-on. Even so, the measured monthly cost never crossed ₩300 — close enough to this guide's conclusion (the cost is negligible either way) that the gap didn't matter much in practice. If you want certainty rather than an estimate, measuring it yourself this way is a reasonable option. Power-monitoring smart plugs are widely available for around $10–15 and remain useful afterward for checking the draw of other small appliances too.
