PSU calculator: how many watts does your PC need?

Most single-GPU gaming PCs need 550 W to 850 W. For entry-level builds (like RTX 4060 or RX 7600), 550 W is the official manufacturer baseline. Mid-range builds (RTX 4070 / RX 7800 XT) need 650 W to 750 W, while high-end systems (RTX 4080 / 4090) need 850 W to 1000 W.

While an RTX 4060 build draws around 310 W at peak, NVIDIA and AMD recommend 550 W for three reasons: (1) Millisecond transient power spikes can briefly exceed rated TDP; (2) Budget PSUs often cannot output 100% capacity on the critical +12V rail; (3) Users may pair the card with higher-wattage CPUs or add drives later.

TDP is a cooling figure, not the most a chip can draw. AMD processors may draw up to their PPT limit, about 1.35 × TDP (88 W for a 65 W Ryzen 5 5600). Intel K processors may draw up to their PL2 limit: 253 W for a Core i7 or i9 K and about 181 W for a Core i5 K, both rated 125 W. A power supply has to cover those peaks, so the calculator uses them.

Electricity cost uses the formula: (Wattage × Hours ÷ 1000) × Electricity Rate. Our calculator transparently shows both Peak Load (100% continuous draw) and Typical Gaming Load (~70% average draw), because games dynamically vary GPU and CPU load across different scenes.

Power supplies run at peak electrical efficiency (highest 80 Plus rating) between 45% and 75% load. Headroom keeps the fan spinning quietly, protects against GPU transient voltage spikes, prevents unexpected shutdowns, and preserves capacitor longevity.

For high-end NVIDIA graphics cards (RTX 4070 Super, 4070 Ti, 4080, 4090 and upcoming 50-series) using the 12V-2x6 / 12VHPWR 16-pin connector, an ATX 3.0/3.1 PSU with a native 16-pin cable is cleanest and safest. For standard 8-pin cards like RTX 4060, any quality 80 Plus ATX 2.4/2.52 unit is fully compatible.