PSU sizing & power budget for your PC build (2026)

Example: a GPU rated at 320W plus a CPU rated at 125W is 445W. Add 125W for the rest of the system to get 570W, then add 25% headroom to land around 710W, which rounds up to a 750W unit.

• Efficiency curve. PSUs run most efficiently and quietest around 40–60% load, not near their rated maximum.
• Transient spikes. Modern GPUs can briefly draw well above their sustained TDP for a fraction of a second. A PSU with no margin can trip its protection circuits under a spike that never even shows up in average power draw.
• Upgrade room. A future GPU upgrade is far more likely to fit inside existing headroom than inside a PSU sized to today's bare minimum.

The 80+ rating measures how much of the power drawn from the wall actually reaches your components versus getting lost as heat. It says nothing about maximum wattage or build quality on its own.

• Bronze is fine on a tight budget, though noticeably less efficient under sustained heavy load.
• Gold is the practical sweet spot for most builds in 2026, a meaningful efficiency step up for a modest price premium.
• Platinum and Titanium mostly pay off on systems under heavy load for long hours, think workstations or always-on servers, where the efficiency gap compounds into real electricity savings.

Not every current GPU needs the newer 12VHPWR/12V-2x6 connector. Check the specific card's spec page rather than assuming based on release date. When a card does require it, prefer a PSU with a native 12VHPWR/12V-2x6 cable over an 8-pin-to-16-pin adapter whenever the PSU supports it natively; native cables remove an extra connection point and are the path the manufacturer actually recommends.

• Open the builder to get a GPU/CPU pairing, then size the PSU from their TDP.
• Rank my PC if you already own a GPU and CPU and just need the wattage math.
• Safe CPU & GPU temperatures, since power draw and heat are closely related.
• GPU PSU power, cables & efficiency (RankedGPU)

How do I calculate what PSU wattage I need?

Add your GPU's rated TDP and your CPU's rated TDP, then add roughly 100–150W for the motherboard, RAM, storage, and fans. Add another 20–30% on top of that total for headroom, and that's your safe target wattage. Round up to the nearest common PSU size: 550W, 650W, 750W, 850W, 1000W.

Why add headroom instead of buying the exact wattage I need?

A few reasons stack up here. PSUs run most efficiently and quietly in the 40–60% load range rather than near their max, transient power spikes from modern GPUs can briefly exceed the rated TDP by a lot, and the extra headroom gives you room for a future GPU or storage upgrade without replacing the whole PSU.

Does 80+ Gold vs Bronze vs Platinum actually matter?

It depends what you're optimizing for. The rating measures efficiency, basically how much input power gets wasted as heat, not maximum output or reliability. Gold is the practical sweet spot for most builds in 2026. Bronze is fine if you're on a tight budget, and Platinum or Titanium mainly pay off on systems under heavy load for long hours, like workstations or always-on rigs.

Do I need a 12VHPWR / 12V-2x6 connector for a modern GPU?

Only if the specific card you're buying actually requires it, so check its spec page rather than guessing from its release date. Plenty of current GPUs still use standard 8-pin PCIe connectors. When a 12VHPWR/12V-2x6 connector is required, use the PSU's native cable rather than an adapter, as long as the PSU supports it natively.

Is a modular PSU worth the extra cost?

Mostly for airflow and cable management, not raw performance. Fewer unused cables stuffed behind the motherboard tray means better case airflow and an easier build to work in. It doesn't change power delivery or efficiency on its own.

Add GPU plus CPU TDP, add 100–150W for the rest of the system, add 20–30% headroom, and round up to the nearest common PSU size. Most 2026 gaming builds land in the 650–850W range, but the exact number depends on the parts you actually pick. Size the PSU after the build, not before.