2026 Lighting Energy Cost Calculator

Estimate lighting energy cost from a list of bulbs by brightness and technology, with a built-in LED savings comparison.

⏱ Updated: 19 Sep 2026

Calculator

Free 2026 lighting energy cost calculator: estimate lighting cost from bulb brightness, technology, quantity, and hours per day, with an LED savings comparison.

Wattage fills in a typical figure for the chosen brightness and technology — edit it if your bulb's box says otherwise.

No default rate is set — electricity prices vary too much worldwide. Enter your own.

Daily Energy
kWh
Monthly Energy
kWh
Annual Cost
If Every Bulb Above Were LED
Estimated Annual Cost
Estimated Annual Savings
Group Daily kWh Monthly kWh Annual Cost

Add a row for each group of bulbs, pick a brightness tier and technology, and set a rate per kWh to estimate lighting cost and what switching to LED could save.

How to Use the 2026 Lighting Energy Cost Calculator

Add a row for each group of identical bulbs. Pick a brightness tier and a bulb technology and the wattage field fills in a typical value for that combination — overwrite it if the bulb in hand is rated differently. Set the quantity and hours per day, add more rows for other fixtures, and set a rate per kWh below the list. Daily, monthly, and annual totals update together, alongside a card comparing your current setup to an all-LED version of the same rows.

The Same Light Output, Very Different Wattage

Lumens measure the light a bulb actually produces; watts measure what it costs to produce it, and the two have gotten steadily less correlated as bulb technology changed. Roughly 800 lumens — a typical living-room bulb's worth of brightness — took a 60 W incandescent filament to produce for most of the twentieth century. A CFL manages the same output around 14 W, and an LED does it closer to 9 W. None of this is a fixed physical law; it's a manufacturing reality that varies by brand and model, which is exactly why the wattage field stays editable after the preset fills it in.

Row Daily Energy (kWh)  = (Watts × Quantity ÷ 1,000) × Hours per Day
Row Monthly Energy (kWh) = Row Daily Energy × 30
Row Annual Energy (kWh)  = Row Daily Energy × 365
Row Annual Cost           = Row Annual Energy (kWh) × Rate per kWh

What Switching Every Bulb to LED Would Actually Save

Alongside the normal totals, the comparison card re-runs the same rows using each brightness tier's typical LED wattage instead of whatever technology is actually selected, then reports the difference. A room lit by four 60 W-equivalent incandescent bulbs running five hours a day is a small, unremarkable-looking line item on its own — until the calculator swaps in 9 W LEDs for the same brightness and the annual gap between the two becomes visible instead of theoretical. Rows already set to LED simply show no difference, which is the point: the comparison only has something to say about the bulbs still running an older technology.