HesapHanem

LED vs Incandescent Savings Calculator

Enter both wattages, daily hours, your kWh rate and bulb count to see the yearly savings.

How it is calculated

The tool compares the power drawn by the old and the new bulb, multiplies the difference over a year of use, and prices it: kWh saved = (incandescent W − LED W) × hours per day × bulbs × 365 ÷ 1000, then yearly saving = kWh saved × rate and monthly saving = yearly ÷ 12. Watts are the real power ratings, hours is the average time each bulb is on per day (above 0 and at most 24), the bulb count must be a whole number, and the rate is your price per kWh. The money figure is shown with a dollar sign but is simply your rate multiplied through. The LED must draw less than the old bulb. A fractional bulb count, more than 24 hours, a zero rate or an LED rated above the old bulb all give no result. Purchase price, bulb lifetime and heating effects are not included, so this is energy cost only.

Worked example

Ten 60 W incandescent bulbs replaced by 9 W LEDs, each on 4 hours a day, electricity at 0.15 per kWh. Wattage saved per bulb: 60 − 9 = 51 W. Energy saved in a year: 51 × 4 × 10 × 365 ÷ 1,000 = 744.60 kWh. Yearly saving: 744.60 × 0.15 = $111.69. Monthly saving: 111.69 ÷ 12 = $9.31.

Try this example →

Common mistakes

  • Entering the wattages on the wrong side: a 60 W bulb belongs in the incandescent box and its ~9 W LED replacement in the LED box; swapped, the tool shows no result because there is no saving.
  • Entering the hours the room is used, rather than the hours each bulb is actually lit; one bulb in a hallway may be on far less than the rest.
  • Using the price in cents (15) instead of per kWh in currency units (0.15), which makes the saving 100 times too big.
  • Entering a monthly bill or a tariff per day instead of the price per kWh.
  • Treating the result as payback: it ignores what the LEDs cost to buy, so divide the purchase price by the yearly saving to estimate payback.

About this calculator

Switching from incandescent to LED bulbs saves money in two compounding ways: LEDs draw roughly 80–90% less wattage for the same light output, and they last far longer, so the savings calculation focuses on the energy side — annual saving = (incandescent watts − LED watts) × hours used per day × 365 × number of bulbs × electricity price per kWh ÷ 1000. A 60W incandescent replaced by an equivalent ~9W LED cuts wattage by around 85% for identical brightness.

Homeowners deciding whether to replace bulbs, and landlords or facility managers upgrading lighting across many fixtures at once, run this calculation because the up-front cost of LED bulbs is higher than incandescents, and the payback period — how long it takes the energy savings to cover that price difference — is what actually determines whether the switch is worth it for a given usage pattern.

Was this helpful?

You can pick up to 3 reactions.

Comments

  • Be the first to comment.

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators