CalcuGrid

What power supply do I need?

Pick the part you already have. Every page carries the full table over the other side, sized on the processor's real power ceiling — not its TDP, which understates a Core i7-13700K by 128 W.

The number on the box is not the number that matters

Processors where the headline TDP most understates the power a supply must cover
Processor Stated TDP Real ceiling Undercount
Core i7-13700K 125 W 253 W +128 W
Core i9-13900K 125 W 253 W +128 W
Core i7-14700K 125 W 253 W +128 W
Core i9-14900K 125 W 253 W +128 W
Core Ultra 7 265K 125 W 250 W +125 W
Core Ultra 9 285K 125 W 250 W +125 W
Ryzen 9 9950X 170 W 230 W +60 W
Ryzen 9 9950X3D 170 W 230 W +60 W
Ryzen 9 7900X 170 W 230 W +60 W
Ryzen 9 7950X 170 W 230 W +60 W

AMD publishes the ceiling as PPT — Package Power Tracking — at 1.35× the stated TDP. Intel publishes it as Maximum Turbo Power, and on the Core i9 parts it is twice the base figure. Every calculation here uses the ceiling.

By graphics card

NVIDIA

GeForce RTX 5090 575 W GeForce RTX 4090 450 W GeForce RTX 3090 Ti 450 W GeForce RTX 5080 360 W GeForce RTX 3090 350 W GeForce RTX 3080 Ti 350 W GeForce RTX 3080 350 W GeForce RTX 4080 SUPER 320 W GeForce RTX 4080 320 W GeForce RTX 5070 Ti 300 W GeForce RTX 3070 Ti 290 W GeForce RTX 4070 Ti SUPER 285 W GeForce RTX 4070 Ti 285 W GeForce RTX 5070 250 W GeForce RTX 4070 SUPER 220 W GeForce RTX 3070 220 W GeForce RTX 4070 200 W GeForce RTX 3060 Ti 200 W GeForce RTX 5060 Ti 180 W GeForce RTX 3060 170 W GeForce RTX 4060 Ti 165 W GeForce RTX 5060 145 W GeForce RTX 5050 130 W GeForce RTX 3050 130 W GeForce RTX 4060 115 W

AMD

Radeon RX 7900 XTX 355 W Radeon RX 7900 XT 315 W Radeon RX 9070 XT 304 W Radeon RX 7800 XT 263 W Radeon RX 7900 GRE 260 W Radeon RX 7700 XT 245 W Radeon RX 9070 220 W Radeon RX 7600 165 W Radeon RX 9060 XT 160 W

By processor

AMD

Ryzen 9 9950X 230 W Ryzen 9 9950X3D 230 W Ryzen 9 7900X 230 W Ryzen 9 7950X 230 W Ryzen 7 9800X3D 162 W Ryzen 9 9900X 162 W Ryzen 7 7800X3D 162 W Ryzen 9 7950X3D 162 W Ryzen 5 7600X 142 W Ryzen 7 7700X 142 W Ryzen 7 5800X3D 142 W Ryzen 9 5950X 142 W Ryzen 5 9600X 88 W Ryzen 7 9700X 88 W Ryzen 5 7600 88 W Ryzen 5 5600X 88 W

Intel

Core i7-13700K 253 W Core i9-13900K 253 W Core i7-14700K 253 W Core i9-14900K 253 W Core Ultra 7 265K 250 W Core Ultra 9 285K 250 W Core i5-13600K 181 W Core i5-14600K 181 W Core Ultra 5 245K 159 W Core i5-12400F 117 W

What the rest of the build costs

Power allowance for everything that is not the processor or the graphics card
Component Each Assumed Notes
Motherboard 25 W 1 Chipset, VRM losses, onboard controllers. Enthusiast boards with extra controllers run higher.
Memory module 3 W 2 Per DIMM. DDR5 at high clocks sits at the top of this.
NVMe SSD 7 W 1 Per drive, at write load. Idle is under a watt.
SATA drive 8 W 0 Per drive. A spinning disk spikes higher on spin-up.
Case fan 2 W 3 Per fan. RGB models draw more for the lighting than the motor.
AIO pump 10 W 0 Per pump. Air coolers draw only their fan, already counted above.

44 W for the default build. Itemised rather than hidden in one lump, so a reader with four drives and nine fans can see why their number differs.

Frequently asked questions

How do I work out what PSU wattage I need?
Add the processor's power ceiling, the graphics card's rated board power and an allowance for the rest of the system — about 44 W for a typical build — then pick a supply large enough that the total sits at about 80% of its rating rather than at its limit.
Should I use my CPU’s TDP to size a power supply?
No. TDP is a thermal design target, not the socket's ceiling. A Core i7-13700K is sold as 125 W and draws 253 W when it boosts — 128 W more than its label. Use AMD's PPT or Intel's Maximum Turbo Power instead.
Why is the recommendation here sometimes higher than the graphics card maker’s?
A card maker publishes one figure per card, and it has to assume some processor. Pair the same card with a Core i9 instead of a Ryzen 5 and the system draws 165 W more, which is more than a whole supply size. Where the build needs less than the vendor's figure, the recommendation stays at theirs — they know how their own board handles transient spikes.
Does a bigger power supply use more electricity?
No. A supply draws what the components ask for, not what it is rated for. A larger unit running at half load is often slightly more efficient than a smaller one running near its limit, so the bigger unit can cost marginally less to run.

A sizing estimate, not a measurement. It adds the processor's power ceiling, the graphics card's rated board power and an itemised allowance for the rest of the system, then leaves headroom so the supply is not running at its limit. Real draw depends on the board's power profile, how far the parts are overclocked, and how a particular graphics card handles transient spikes. Treat a result within 50 W of a supply's rating as a reason to choose the next size up. Processor figures from AMD and Intel published processor specifications; card figures from Manufacturer specifications, shared with the GPU power dataset.

Data on this page last verified .

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