PSU Wattage Calculator
Select your CPU and graphics card, add the rest of your parts, and get an estimated peak load with a recommended power supply size.
How to use the PSU Wattage Calculator
- Pick your CPU and graphics card. Choose Custom to enter a wattage yourself.
- Enter memory sticks, drives, fans and the cooler type.
- Tick the overclock box if you overclock. It adds margin to the CPU and GPU.
- Use the recommended wattage. The table shows where the estimate comes from.
How it is calculated
The estimate adds the CPU maximum power, the graphics card board power, about 50 W for the motherboard, 4 W per memory stick, 7 W per NVMe drive, 3 W per SATA SSD, 8 W per hard drive, 2.5 W per fan, the cooler, and your extra devices. Overclocking adds 25% to the CPU and 10% to the GPU.
The recommendation multiplies the total by 1.3 and rounds up to a common PSU size. That leaves room for short power spikes, aging and efficient operation. These are typical figures, not measurements of your exact parts.
Hardware performance values are approximate relative tiers from public review data, rounded by hand. They are estimates, not RaggisHub measurements.
Frequently asked questions
How much headroom should a PSU have?
About 30% above your estimated peak load is a common target. It keeps the unit away from its limit during spikes and leaves room for later upgrades.
Does a bigger PSU use more electricity?
No. A PSU only supplies what the computer asks for. A larger unit simply runs at a lower share of its capacity.
Does the 80 PLUS rating tell me the size I need?
No. The rating describes efficiency at set loads. Choose the size from your load, then pick the efficiency tier you want.
Which connectors matter for a new GPU?
Check the card's power connector, such as 12V-2x6 or several 8-pin PCIe plugs, and confirm the PSU provides it with its own cables.