Quick answer: To replace a 60 W incandescent bulb, look for an LED with at least 800 lumens; that is ENERGY STAR's minimum brightness target. According to the FTC, an LED producing about 800 lumens can use about 9 W. Sources: ENERGY STAR brightness chart and FTC bulb-shopping guide.
An LED's equivalent wattage describes the incandescent brightness it replaces, while its actual wattage tells you the power it draws. This guide covers household incandescent replacements: use the chart to choose a lumen target, compare actual LED power, then estimate the running cost for your own hours and electricity rate.
LED watt-equivalent chart: match the lumen target
Choose the lumen target first. ENERGY STAR lists minimum lumens for each incandescent wattage, so these are replacement thresholds, not claims that every old bulb produces exactly that output. ENERGY STAR brightness chart
| Old incandescent wattage | Minimum replacement brightness | LED power range listed by DOE FEMP |
|---|---|---|
| 40 W | 450 lumens | 4.5–7 W |
| 60 W | 800 lumens | 5.9–10.5 W |
| 75 W | 1,100 lumens | 9.5–14 W |
| 100 W | 1,600 lumens | 10.5–18 W |
| 150 W | 2,600 lumens | Not supplied in the cited table |
The brightness thresholds come from ENERGY STAR. According to DOE FEMP's purchasing table, the power ranges shown apply to ENERGY STAR-listed A-type LEDs with an E26 base. They describe that table's products, not mandatory wattage limits for every LED.
Read across the row when shopping. The old wattage identifies your starting point; the lumen column identifies the output to seek; the LED wattage column shows why there is no single universal conversion factor. Do not fill the missing power range by extrapolating from another row: compare the actual wattage of bulbs meeting the lumen target.
What “watt equivalent” means on the box
Equivalent wattage is a brightness comparison, not the LED's electrical consumption. According to ENERGY STAR, packaging may use wording such as “60 watt replacement”; the agency recommends choosing the lumens you need, then the lowest wattage. ENERGY STAR shopping guidance
The distinction matters when entering a bulb into a cost calculator. Use its actual power rating for the LED calculation and the old bulb's actual rating for the incandescent calculation. Entering the replacement claim as the LED's power would erase the very saving you want to measure.
Watts still matter for energy use. They simply do not measure brightness: lumens describe light output, and more lumens means a brighter bulb. FTC bulb-shopping guide Compare those separate quantities instead of assuming a higher-wattage LED must produce more light than another model.
Read the Lighting Facts label before choosing
Use the Lighting Facts panel to separate brightness, consumption and appearance. The FTC lists lumens, estimated yearly energy cost, expected life in years, warm-to-cool light appearance, wattage and mercury information among its contents. FTC label guide
A practical shopping sequence is:
- Find the replacement lumen target in the chart above.
- Compare the printed lumens of candidate bulbs against that target.
- Compare actual watts among bulbs meeting your brightness requirement.
- Choose the light appearance you prefer, and use your own operating hours and electricity rate for the cost estimate.
The cost on the label uses standardized assumptions. The supplied snapshot of 16 CFR Part 305, general service lamps label content, specifies 3 hours per day and $0.11 per kWh for estimated energy cost; life in years also uses 3 hours per day. It specifies brightness in average initial lumens rounded to the nearest five. 16 CFR Part 305 label requirements
That makes the printed cost useful for comparing packages on a common basis. It does not make it a prediction of your bill if your usage or tariff differs. Keep light appearance separate from the brightness decision, too: the label provides both fields so you can select each deliberately.
Compare efficiency with lumens per watt
Divide light output by actual wattage to compare efficacy. The regulatory definition of lamp efficacy is light output divided by wattage, expressed in lumens per watt. 16 CFR Part 305 definitions
Formula: efficacy (lm/W) = light output (lumens) ÷ actual power (W).
For a worked comparison, the assumed inputs are an incandescent and an LED each producing 800 lumens, drawing 60 W and 9 W respectively. These inputs follow the FTC's approximate example; according to the FTC, those bulbs can deliver the same light output at those different powers. FTC comparison
- Incandescent efficacy = 800 ÷ 60 = 13.333… ≈ 13.3 lm/W.
- LED efficacy = 800 ÷ 9 = 88.888… ≈ 88.9 lm/W.
- Power reduction at equal output = (60 − 9) ÷ 60 × 100 = 51 ÷ 60 × 100 = 0.85 × 100 = 85%.
Those are calculations for the assumed pair, not a promise for every replacement bulb. The LED savings calculator uses 0.15 as the calculator's planning figure for incandescent-to-LED power: with an assumed 60 W input, estimated LED power = round(60 × 0.15) = round(9) = 9 W. Use the lumen chart to establish brightness equivalence before relying on that planning estimate.
Worked example: monthly electricity savings
Running cost depends on actual power, quantity, operating time and your electricity rate. The electricity cost calculator multiplies total watts by daily hours, divides by 1,000 to obtain daily kWh, then multiplies by days and the rate.
Assumed inputs: five 60 W incandescent bulbs replaced by five 9 W LEDs; both choices meet the same brightness need; 4 hours of use per day; 30 days in the month; electricity at $0.20/kWh. These are illustrative inputs, not a household average or a quoted tariff.
Formula: monthly cost = (watts per bulb × quantity × hours/day ÷ 1,000) × days/month × price/kWh.
For the incandescent bulbs:
- Total power = 60 × 5 = 300 W.
- Daily energy = 300 × 4 ÷ 1,000 = 1,200 ÷ 1,000 = 1.2 kWh.
- Monthly energy = 1.2 × 30 = 36 kWh.
- Monthly cost = 36 × $0.20 = $7.20.
For the LEDs:
- Total power = 9 × 5 = 45 W.
- Daily energy = 45 × 4 ÷ 1,000 = 180 ÷ 1,000 = 0.18 kWh.
- Monthly energy = 0.18 × 30 = 5.4 kWh.
- Monthly cost = 5.4 × $0.20 = $1.08.
Monthly savings = $7.20 − $1.08 = $6.12, with energy savings of 36 − 5.4 = 30.6 kWh. This compares electricity consumption only; bulb purchase costs are excluded. Change the assumed inputs to match the bulbs and usage you are comparing.
FAQ
What LED replaces a 60 W incandescent bulb?
Choose at least 800 lumens, the minimum in ENERGY STAR's chart. According to DOE FEMP, its listed LEDs at that output use 5.9–10.5 W, so a fixed wattage rule is less useful than the lumen rating.
What LED wattage replaces a 100 W bulb?
Start with at least 1,600 lumens, as listed by ENERGY STAR. According to DOE FEMP's table, the corresponding listed LED range is 10.5–18 W.
Is a 6 W LED always equivalent to a 60 W bulb?
No: its wattage alone does not establish its light output. Look for the 800-lumen minimum for that replacement class in ENERGY STAR's chart, rather than assuming the power rating guarantees it.
Does “60 watt replacement” mean the LED uses 60 W?
No. According to ENERGY STAR, this is an equivalent-wattage packaging claim; read the actual wattage separately when calculating consumption.
Why does my calculated cost differ from the box?
Your hours or electricity rate may differ from the label's assumptions of 3 hours per day and $0.11/kWh. Those assumptions are specified in the supplied 16 CFR Part 305 snapshot; substitute your own inputs for a personal estimate.
Jack Shi
Founder & editor, LEDaskJack Shi builds and writes LEDask, an independent LED-lighting tools project operated by clooms. He designs the calculators, checks their formulas and reference values against published engineering data, and writes the guides across the site.
