The power supply rating is not your actual draw
A 500-watt or 750-watt power supply rating is the maximum the unit can deliver, not what it draws every minute. During an intensive gaming session the system may pull 60-80% of that rating, but at idle or during lighter tasks it can drop to 100 watts or less.
For a monthly estimate, separate gaming hours at medium-to-high load from the remaining hours the computer stays on for browsing, streaming, or downloads. Add monitor power separately unless the PC supplies it through a USB port.
Typical gaming PC power ranges
An entry-level system with an efficient graphics card may average 200-300 watts during a game. A high-end desktop with a flagship GPU and a power-hungry processor can reach 500-600 watts or more under full load, but rarely sustains that for the entire session.
- Measure with a plug-in watt meter for the most accurate room-level result.
- Older graphics cards and multi-GPU setups can draw significantly more.
- RGB lighting, liquid cooling pumps, and multiple drives add a modest continuous load.
Monthly cost at a typical electric rate
At an illustrative 18 cents per kWh, a 500-watt gaming load for four hours daily and 100 watts for another four idle hours uses about 2.4 kWh per day. That works out to roughly 72 kWh per month, or about $13 in energy charges before monitor and peripheral power is added.
Replace the gaming load assumption, hours, and local rate with your own numbers. If the same PC doubles as a workstation running heavy rendering or modeling loads, use the continuous operating power for all active hours.
Reduce power without reducing performance
Frame-rate caps, undervolting, and an efficiency-oriented power plan can lower the average draw during less demanding scenes. Enabling V-Sync or a frame limiter stops the GPU from rendering frames the monitor cannot display, which directly cuts wattage during most gameplay.
- Enable the operating system's power saver plan for non-gaming hours.
- Turn off the monitor or let it sleep when the computer is left running downloads.
- Upgrade from an older power supply only when the current unit lacks the needed connectors or efficiency certification.
Rate source and limits
The default rate is the EIA U.S. residential average for April 2026, retrieved July 16, 2026. It is an average revenue per kilowatt-hour, not a quote for your utility plan. Fixed fees, taxes, tiers, and time-of-use prices can change the bill.
Open the EIA source