PSU Wattage Calculator
Size your power supply with honest headroom math.
Pick your CPU and GPU (or enter wattages manually), add your accessories, and get a recommended PSU wattage with transparent assumptions — minimum, comfortable, and the retail tier to buy.
Recommendation
Recommendations are planning estimates, not electrical or purchasing advice. The hardware figures behind them are vendor-published; your exact board-partner model and build can still differ.
One or more selected parts have a figure we could not confirm against the manufacturer’s published specification. Check the official spec page before buying.
PSU tier to buy
750 W
Common retail sizes: 450, 550, 650, 750, 850, 1000, 1200, 1600 W.
Estimated system load
529 W
CPU peak + GPU peak + accessories (117 W)
Recommended minimum PSU
650 W
Estimated load x 1.1 floor, rounded up to a retail size.
Recommended comfortable PSU
662 W
Estimated load x 1.25 for your profile.
Suggested efficiency class
80 PLUS Gold. The 650-850 W range is where Gold units hit the sweet spot of price, efficiency, and quiet operation — this is what most builders should buy.
Safety notes
- These figures are planning estimates based on vendor-published limits, not measurements of your specific parts. Verify CPU, GPU, and PSU specifications on the manufacturers' official pages before purchase.
- PSU quality matters as much as wattage. A reputable current-generation unit at the recommended tier beats an oversized bargain unit every time.
- Never mix modular cables between different PSU brands or models — pinouts differ and mismatched cables can destroy hardware.
- If your GPU uses a 16-pin (12VHPWR / 12V-2x6) connector, seat it fully and avoid tight bends near the plug.
Methodology — Recommendations are planning estimates, not electrical or purchasing advice. The hardware figures behind them are vendor-published; your exact board-partner model and build can still differ.
Frequently asked questions
How accurate is this PSU wattage calculator?
It is a planning estimate, not a measurement. We sum vendor-published power limits (GPU TGP/TBP and CPU PPT/MTP) plus conservative accessory allowances, then add headroom. Real draw is usually lower, but sizing against the ceiling keeps you safe. Always confirm the final choice against your exact parts' official specifications.
Why does the recommendation round up to a specific wattage?
Power supplies are sold in fixed sizes (450, 550, 650, 750, 850, 1000, 1200, 1600 W). We round the comfortable target up to the next real size so the number you see is one you can actually buy.
What headroom does it add?
The comfortable recommendation multiplies estimated load by 1.25 for standard use, 1.35 for light overclocking, or 1.45 for future-upgrade headroom. The minimum figure uses a 1.1x floor. Headroom covers transient spikes, efficiency, quiet operation, and capacitor aging over time.
Can I use it if my exact CPU or GPU is not listed?
Yes. Switch on the manual entry option for the CPU and/or GPU and type the peak wattage from the vendor's spec page (PPT/MTP for CPUs, TGP/TBP for GPUs). The tool works entirely on the numbers you provide.
Does a higher-wattage PSU use more electricity?
No. A power supply only delivers what the system draws, so a 1000 W unit running a 400 W system draws about the same from the wall as a 650 W unit would. Oversizing mainly wastes money and can slightly reduce efficiency at very low load.
Related tools
Guides
What PSU Do You Need for an RTX 5070?
Worked PSU sizing for the NVIDIA GeForce RTX 5070: estimated system load with a modern CPU, recommended wattage tiers, and when 650W vs 750W makes sense.
Is 750W Enough for an RTX 5070 Ti + Ryzen 7 9800X3D?
Load math for the RTX 5070 Ti + Ryzen 7 9800X3D combo: estimated draw, why 750W is the comfortable tier, and when 850W is worth it.
What PSU Do You Need for an RX 9070 XT?
PSU sizing for the AMD Radeon RX 9070 XT: worked load estimates with heavy and light CPUs, connector notes for partner cards, and the 650W vs 750W decision.
What PSU Do You Need for an RTX 4070 + Ryzen 5 7600?
PSU sizing for the popular RTX 4070 + Ryzen 5 7600 pairing: real load math, why a quality 550W unit is enough, and why NVIDIA's 650W guidance is more conservative.
How Much PSU Headroom Do You Actually Need?
Why PSU calculators add 25-45% on top of estimated load: transient spikes, efficiency and noise sweet spots, capacitor aging, and upgrade room — with worked numbers.
ATX 3.0 vs ATX 3.1: Do You Need a New PSU for the RTX 50 Series?
Intel publishes every revision of the ATX design guide openly, so the two can be compared line by line. The transient requirement did not change, the connector did — and no official document says an ATX 3.0 unit is insufficient for an RTX 50 card.
Hardware reference
PSU by build (GPU + CPU pairings)
Ready-made answers for popular graphics card and processor combinations.
PSU & connectors for every GPU
Per-card board power, recommended wattage and connector, computed from vendor data.
Power reference for every CPU
Base and peak power (TDP/PPT, PBP/MTP) with a cooling-class guideline.