TechCompare LogoTechCompare
Back to Home

Power Cost Estimator

Calculate electricity costs for your tech.

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
$14.69
Yearly Cost
$178.70
993 kWh / year

About this tool

The Power Cost Estimator turns wattage into money. Enter the average draw of a device in watts, how many hours per day it runs, and your local electricity rate, and it returns daily, monthly, and annual cost, plus total kWh consumption so you can compare against your utility bill. 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 actually 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 supports any currency and rate structure, so it works whether you pay €0.35/kWh in Europe, $0.12/kWh in parts of the US, or anything in between.

Formula

Annual cost = (watts × hoursPerDay × 365 ÷ 1,000) × rate. The division by 1,000 converts watt-hours to kilowatt-hours, which is how utilities bill you. A 100 W device running 24/7 consumes 876 kWh/year; at €0.30/kWh that's €263.

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 Data Read 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 1000W power supply means the computer draws 1000W constantly. In reality, a high-end gaming PC might only draw 80W to 120W while browsing the web or watching YouTube (idle state). It only ramps up to its maximum power draw during intense workloads like rendering video or playing demanding 3D games. To get an accurate annual cost, you should estimate your blended average wattage based on how you actually spend your time on the machine.

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. Cut that to 8 hours per day of active gaming plus idle the rest and it drops to roughly €260/year. Sleep mode and turning the PC off when not in use are the biggest levers.
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 your electricity rate (e.g. €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 assumes the wattage you enter is the average over runtime. Real devices spike, idle, and have standby draw. Measure with a cheap wall-socket power meter for the most accurate baseline, then use the estimator to project costs for different usage scenarios.
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.

Related tools

Data Read Visualizer

Visualize the massive speed difference between CPU cache, RAM, and storage.

Use tool ➜

RAM Latency Calculator

Convert DDR3/DDR4/DDR5 timings (CL, tRCD, tRP, tRAS) into true latency in nanoseconds.

Use tool ➜

RAID Calculator

Calculate usable capacity and fault tolerance for RAID 0, 1, 5, 6, and 10.

Use tool ➜

Data Transfer Calculator

Estimate transfer times for files over USB, WiFi, Ethernet, and more.

Use tool ➜