PSU Calculator
Find the right power supply for your PC build. Select your CPU, GPU, and peripherals below to get a minimum and recommended PSU wattage. Our database covers 306+ CPUs and 142+ GPUs with real TDP values so your estimate is accurate - not just a generic guess.
Unlike calculators that just add up TDPs, we model transient power spikes: modern GPUs briefly draw up to 2x their rated TDP (the excursion limit the ATX 3.0/3.1 spec is built around), and CPUs overshoot under boost. An ATX 3.0/3.1 PSU at our recommended wattage (sustained draw plus 25% headroom) is rated to absorb that peak by design - we show the spike estimate either way, and if you are reusing an older ATX 2.x unit, we tell you how much bigger to go so it never trips over-power protection. A PSU running at 50-80% load is also quieter, cooler, and lasts longer than one pinned at 100%. Want the full breakdown by GPU? Read our PSU wattage guide, or check your parts are balanced with the bottleneck calculator.
Looking for an OuterVision replacement? OuterVision, the long-time default PSU calculator, shut down in early 2025. This tool is a maintained, independent alternative - the hardware database and pricing behind it are updated daily.
PSU Wattage Calculator
Select your CPU, GPU, and peripherals to find out the minimum and recommended power supply wattage for your build.
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Peripherals & Storage
Frequently Asked Questions
Frequently Asked Questions
How much wattage does my PC actually need?
Your PC needs enough wattage to power all components under peak load, plus headroom for efficiency and power spikes. We recommend at least 25% more than your total estimated draw. For example, a system drawing 500W should use a 650W PSU.
What happens if my PSU is too small?
An undersized PSU can cause random shutdowns, crashes, and system instability - especially under heavy loads like gaming or rendering. In extreme cases, it can damage components. Always go with at least the minimum recommended wattage.
Is it bad to have a PSU that is too powerful?
No. A higher-wattage PSU will not force extra power into your components - it only delivers what they draw. A larger PSU gives you more upgrade headroom, runs cooler, and can be quieter. The only downside is paying more upfront.
What does 80+ Gold certification mean?
80+ certification measures power supply efficiency - how much AC power from the wall gets converted to usable DC power. 80+ Gold is about 90% efficient and is the best value for most gaming builds. Platinum and Titanium are better but cost significantly more.
Should I account for future GPU upgrades when buying a PSU?
Yes. Next-gen GPUs tend to draw more power. Buying a PSU with 200-300W of headroom over your current draw gives you room to upgrade your GPU without replacing the power supply.