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PC Power Cost Calculator

Enter watts, hours per day, and your kWh rate to see daily, monthly, and yearly electricity cost for any PC or device.

Device Configuration

W

Not sure? Check PCPartPicker or BuildCores.

Effective Power: 680W

Hours
$/kWh

Not sure? Check global prices on World Population Review.

Daily Cost
$0.49
Monthly Cost
$14.89
Yearly Cost
$178.70
993 kWh / year

How to use this tool

  1. Enter the device wattage and utilization

    Enter the device's maximum or representative load draw in watts, then set utilization to the share of that power it averages while running. For example, 500 W at 80% utilization becomes 400 W effective power. If a wall-socket meter already gives you an average draw, enter that value and set utilization to 100%. Don't use a PSU's rated capacity as the device draw.

  2. Set the hours per day it runs

    Enter how many hours per day the device follows that usage pattern. A gaming PC used 4 hours a day gets 4, while an always-on NAS gets 24. The tool multiplies watts × (utilization ÷ 100) × hours × 365, then divides by 1,000 to get annual kWh.

  3. Enter your electricity rate

    Type a flat or user-computed blended electricity price in USD per kWh, such as $0.30. The calculator does not model currencies, time-of-use rates, tiers, demand charges, or fixed fees, so convert your bill to a single USD rate before entering it.

  4. Read daily, monthly, and annual cost

    The calculator returns the cost per day, per month, and per year along with total kWh consumed. Use those figures to compare against your utility bill or weigh one device against another before buying or upgrading.

About this tool

The Power Cost Estimator turns wattage into money. Enter a device's maximum or representative load draw, set utilization to estimate its average power while running, add daily runtime and your local electricity rate, and the calculator returns daily, monthly, and annual cost plus total kWh consumption. If you already measured average draw at the wall, use 100% utilization. It's the fastest way to check whether leaving a gaming PC on overnight, running a home server 24/7, or upgrading to an OLED TV is going to be noticeable on your bill.

Use it to size an uninterruptible power supply, decide whether it's cheaper to run a 4090 less often or a 4070 more often, or justify (or veto) a homelab build to your family. The tool uses a single USD price per kWh, so use a flat rate or calculate a blended rate from your bill before entering it.

Formula

Annual cost = watts × (utilization ÷ 100) × hoursPerDay × 365 ÷ 1,000 × rate. Utilization converts the entered maximum or load wattage into effective average power. The division by 1,000 converts watt-hours to kilowatt-hours, which is how utilities bill you. A 100 W device at 100% utilization running 24/7 consumes 876 kWh per year and costs about $263 at $0.30/kWh.

When to use it

Ideal for comparing two GPUs or CPUs with different TDPs over their expected lifespan, sizing your electricity budget before building a server or mining rig, or deciding how aggressively to tune your PC's idle power states. Pair with the RAM Latency Calculator and Memory & Storage Latency Visualizer to weigh performance against efficiency for a specific workload.

Understanding Idle vs. Load Power

One of the most common mistakes when estimating PC running costs is assuming a 1000 W power supply means the computer draws 1000 W constantly. In reality, a high-end gaming PC might draw 80 W to 120 W while browsing the web or watching video, then ramp up during rendering or demanding games. Use the utilization slider when one percentage reasonably represents the mix. For more accuracy, calculate active and idle periods as separate scenarios. If you enter a measured blended average, set utilization to 100%.

Popular device profiles

Pre-computed yearly and monthly cost for the devices visitors ask about most, gaming PCs, laptops, servers, and consoles.

850 W gaming PC
Current high-end rig running a few hours a day
View details ➜
500 W gaming PC
Mainstream mid-range build
View details ➜
100 W home server
NAS or always-on home lab node
View details ➜

Frequently asked questions

How much does it cost to run a gaming PC 24/7?
At 300 W continuous draw and $0.30/kWh, a gaming PC left on 24/7 costs about $788 per year. If it draws 300 W for 8 hours per day and is off or asleep otherwise, that active use costs roughly $263 per year. Add any idle or standby draw for the other 16 hours separately.
How do I calculate kWh from watts?
Multiply wattage by hours, then divide by 1,000. A 500 W device running for 4 hours uses 500 × 4 ÷ 1,000 = 2 kWh. Multiply by the flat or blended USD rate entered in the calculator, such as $0.30/kWh, to get the cost.
What uses more electricity: an RTX 4090 or a typical fridge?
Peak power, the RTX 4090 wins (450 W vs roughly 100-150 W compressor draw). Annual consumption is the opposite: a fridge runs 24/7 at an average of 40-50 W, adding up to around 400 kWh/year, more than many gaming PCs use when run only a few hours daily.
Does a 1000 W PSU use 1000 W all the time?
No. A PSU is rated for its maximum output capacity; actual draw depends on what the components need. A system with a 1000 W PSU at idle might pull 80 W from the wall, jumping to 400-600 W under gaming load.
How much does an always-on TV or server cost per year?
At 100 W continuous draw and $0.30/kWh, any device running 24/7 costs $263/year. A home NAS at 50 W costs $131/year, and a 65-inch OLED TV watched 4 hours/day at 150 W costs about $66/year.
Why is my electricity bill higher than the estimator predicts?
The estimator treats the wattage input as a maximum or representative load and multiplies it by utilization to estimate average draw while the device runs. If you enter an average measured with a wall-socket meter, set utilization to 100% so it isn't reduced twice. Add idle and standby periods as separate scenarios when they fall outside the hours entered.
How can I reduce my PC's power consumption?
The most effective methods are undervolting your CPU and GPU (which lowers voltage without sacrificing performance), enabling aggressive sleep states so the PC draws minimal power when inactive, and capping your framerate in games to your monitor's refresh rate so the GPU doesn't render unnecessary frames.
What is a TDP and is it the same as power draw?
TDP stands for Thermal Design Power. It is a metric used by manufacturers to indicate the amount of heat the cooling system needs to dissipate, not the exact electrical wattage drawn from the wall. While the two numbers are closely correlated (a 250W TDP CPU will draw roughly 250W under full load), they are not identical, and modern CPUs can often boost slightly above their rated TDP.

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