How do you calculate annual lighting energy cost?

Multiply connected load in kW by annual operating hours by the electricity rate. For 15 kW running 3,500 hr/yr at $0.13/kWh, that's 52,500 kWh costing $6,825 per year.

What is the cost per fixture per year?

Divide total annual cost by the fixture count. With $6,825 across 100 fixtures, each fixture costs about $68.25 per year to run.

How do I find total connected load?

Add the input wattage of every fixture, including driver and ballast losses, and convert to kilowatts. For 100 fixtures at 150 W each, that's 15,000 W, or 15 kW.

Does this number include demand charges?

No. This is energy (kWh) cost only. Many commercial bills also carry a demand charge on peak kW, which lighting can contribute to but isn't captured here.

How much can an LED retrofit cut this cost?

Swapping high-wattage HID or fluorescent for LED commonly cuts connected load 40-60%, which scales the annual cost down proportionally. Run the retrofit payback calculator with the savings.

What's the hourly energy cost good for?

It quantifies what each hour of unnecessary runtime costs. At $1.95/hr here, leaving lights on an extra two hours a day adds roughly $1,000 a year, which is what justifies sensors and scheduling.

Lighting, LEDs & Electrical Fixtures calculator

Annual LED Fixture Energy Cost Calculator

Annual fixture energy cost turns a lighting installation's connected load into the dollars it burns over a year. Facility managers, energy engineers, and lighting contractors use it to baseline a building's lighting spend, build the savings case for an LED retrofit, and allocate cost per fixture in a budget. Lighting often runs 10-15% of a commercial facility's electric bill, so a credible annual number is the foundation for any efficiency project. The calculation also exposes the hourly burn rate, which is what makes occupancy sensors and scheduling pay off.

What this calculator does

Calculate the annual electricity cost of operating an installed LED fixture system. Enter total connected load, annual operating hours, electricity rate, and fixture count to get total annual energy cost and cost per fixture per year.
Use this when preparing an energy audit, comparing LED vs. legacy fixture operating cost, building an energy cost model for a facility, justifying an LED upgrade with annual savings, or setting energy budgets for a lighting installation.
It computes the total annual electricity cost of a lighting load and breaks it down to cost per fixture and per hour.

Formula used

Annual energy cost = total connected load (kW) x annual operating hours x electricity rate
Annual energy cost per fixture = total annual cost / number of fixtures

Inputs explained

Total connected load:
Annual operating hours:
Electricity rate:
Number of fixtures installed:

How to use the result

Use it to baseline current lighting spend, justify a retrofit, or allocate energy cost across a fixture inventory.
It assumes constant connected load and a flat energy rate, so it won't capture dimming, demand charges, or time-of-use tariffs without adjustment.

Current U.S. benchmarks

As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.
The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate annual lighting energy cost? Multiply connected load in kW by annual operating hours by the electricity rate. For 15 kW running 3,500 hr/yr at $0.13/kWh, that's 52,500 kWh costing $6,825 per year.
What is the cost per fixture per year? Divide total annual cost by the fixture count. With $6,825 across 100 fixtures, each fixture costs about $68.25 per year to run.
How do I find total connected load? Add the input wattage of every fixture, including driver and ballast losses, and convert to kilowatts. For 100 fixtures at 150 W each, that's 15,000 W, or 15 kW.
Does this number include demand charges? No. This is energy (kWh) cost only. Many commercial bills also carry a demand charge on peak kW, which lighting can contribute to but isn't captured here.
How much can an LED retrofit cut this cost? Swapping high-wattage HID or fluorescent for LED commonly cuts connected load 40-60%, which scales the annual cost down proportionally. Run the retrofit payback calculator with the savings.

Last reviewed 2026-05-12.