What Your Monitor (or Triple-Monitor Setup) Actually Costs to Run

A certified computer monitor costs about $8.49 a year to run at the US average electricity rate — so little that even a three-monitor desk setup, run full-time on workdays, costs less than most households spend on a single lightbulb left on by accident.

What a monitor actually draws

ENERGY STAR certifies monitors against a Total Energy Consumption (TEC) requirement that measures power draw in On Mode and Sleep Mode and scales with screen area and resolution, with eligibility limited to screens over 12 inches. Across 1,482 certified models in WattCost's dataset, annual use ranges from 11.11 kWh to 402.94 kWh — a 36x spread, with the high end dominated by large digital-signage-class displays rather than typical desk monitors.

The multi-monitor math

For a realistic desk setup: the median certified monitor uses 45.08 kWh a year. Three of them come to about 135 kWh, or roughly $19–$25 a year depending on your state's rate — a rough estimate built directly from certified per-model figures, not a guess. That number covers only the monitors; it doesn't include the computer driving them, which for a desktop or gaming PC is a separate, much larger, and uncertified load — see the gaming PC calculator for that side of the desk.

The details most shoppers never see

Certification comes with requirements that don't show up on a spec sheet: the screen has to exceed 12 inches to qualify at all, and any external power supply bundled with the monitor must meet Level VI efficiency marking under the International Efficiency Marking Protocol. It's a small detail, but it's one more reason two monitors that look identical on a store shelf can differ in standby draw.

Screen size still matters, just less than you'd think

Compare the 24-inch, 27-inch, 32-inch, and 34-inch ultrawide facets directly and the trend holds, but the gap between the most and least efficient models at any single size is often larger than the gap between adjacent sizes — panel type and brightness settings move the number more than the diagonal measurement does. ENERGY STAR's own program-wide estimate is that certified monitors run about 7% more efficient than standard options, a modest but real baseline before you even compare specific models.

Refresh rate plays a role too: a high-refresh-rate gaming monitor (144Hz and above) typically draws more power in On Mode than a standard 60Hz panel of the same size, since a faster refresh and the higher peak brightness gaming panels often carry both cost energy — one more reason two 27-inch monitors can post noticeably different certified figures.

Your state matters, but the absolute numbers stay small

At the US average rate, the median monitor costs $8.49 a year. In North Dakota that's $5.57; in Hawaii it's $21.02 — a real multiple, but a small absolute swing compared to almost anything else in the house.

What actually moves the number

• Panel type and brightness. These move power draw more than screen size alone within a given diagonal.
• Sleep-mode behavior. A monitor that actually sleeps when idle uses far less than one left in a bright, active state overnight.
• How many you run. Multi-monitor setups scale linearly — three monitors cost roughly three times one, unlike most other appliance categories.

FAQ

How much electricity does a computer monitor use? Certified models in WattCost's dataset range from 11.11 to 402.94 kWh a year, with a median of 45.08 kWh — about $8.49 a year at the US average rate.

What does a 3-monitor setup cost to run? Roughly $19–$25 a year at typical electricity rates, based on three median-efficiency certified monitors — not counting the computer itself.

Is my computer or my monitor the bigger cost? Almost always the computer. See the gaming PC calculator for an uncertified but transparent wattage-based estimate, since desktops aren't ENERGY STAR-certified for annual kWh the way monitors are.

Does monitor size affect running cost? Yes, but panel type and brightness settings often matter more. Compare certified monitors by size directly.

How is a monitor's certified energy use measured? Through ENERGY STAR's Total Energy Consumption (TEC) test, which weighs On Mode and Sleep Mode power against screen area and resolution.

For the monitor's place in a full desk setup — including the PC and router — see what a home office actually costs to run.