PSU FIT CHECK — SPEC LOOKUP
Pick your GPU and CPU. Get the wattage and connectors you actually need — no account, just the numbers.
Common questions
How much wattage do I actually need?
Your graphics card's rated power, plus your CPU's stock power limit, plus about 150W for the motherboard, drives and fans. Then 20% headroom on top, rounded up to a real PSU size. The calculator above does exactly that, and how it works explains where each number comes from.
Why is my number different from what Nvidia or AMD recommend?
Card makers publish one minimum for everyone, based on a high-end test PC. Nvidia's RTX 50 minimums, for example, assume a Ryzen 9 9950X. A build with a 6-core CPU can need less, and one with an Intel K-series chip can need more.
Is buying a bigger PSU than I need a waste?
It won't hurt anything. A power supply only delivers what your parts pull, so a 1000W unit in a 500W build doesn't use 1000W. The cost is mostly up front. The one catch: a hugely oversized unit idles at a tiny share of its rating, where power supplies are least efficient. More in 80 Plus ratings explained.
Do I need a new PSU for a card with the 16-pin plug?
Usually not. Those cards come with an adapter that takes separate 8-pin PCIe cables, so you need enough watts and enough separate cables. See Can I use my old PSU with an RTX 50 series card?
Does this account for overclocking?
No. The numbers are for stock settings. If you overclock, use a motherboard that removes Intel's power limits, or have a factory-overclocked card rated above the reference spec, go up one size.