Interactive tool
PSU Sizing Calculator for a Mining PC
Pick the right power supply wattage for your CPU + GPU mining rig. Adds component draws, applies headroom, and checks the PSU sweet spot.
Components
Use sustained mining draw, not the manufacturer peak. RTX 3060 ≈ 170W, RTX 3070 ≈ 220W, RX 6700 XT ≈ 230W.
Headroom & efficiency
Component draw
365 W
CPU + GPUs + other
With headroom
475 W
+ 30%
Recommended PSU
550 W
80 Plus Gold (~87% at 50% load)
PSU sweet spot
At the recommended size, this build draws roughly 66.4% of the PSU's rated capacity. That's inside the 40-70% sweet spot - the PSU runs at peak efficiency, fans stay quiet, and it lasts longer.
Skip no-name "1200W" PSUs from marketplaces - they lie about output. Stick to known brands (Corsair, Seasonic, EVGA, Be Quiet, FSP).
Methodology
How this calculator works
Adds the sustained draw of each component, applies a headroom margin, and rounds up to the next commonly sold power supply size. It is deliberately conservative, because a mining load is sustained for weeks rather than bursting for seconds like a game.
The arithmetic
- component draw = CPU TDP + (GPU count * watts per GPU) + other components
- sized draw = component draw * (1 + headroom percent / 100), default headroom 30%
- recommended = the next size up from 450, 550, 650, 750, 850, 1000, 1200, 1600 W
- load at recommended = component draw / recommended wattage
- the 40-70% load band is flagged as the efficiency sweet spot
What it assumes
- CPU TDP and GPU watts are sustained mining draw, not idle or peak-boost figures.
- The "other" figure covers motherboard, RAM, drives, fans, and risers.
- 80 Plus efficiency percentages are the nominal ratings at 50% load.
Where it breaks down
- TDP is a thermal rating, not a power measurement. Real draw can exceed it, particularly on GPUs under sustained load.
- Transient spikes on modern GPUs can briefly exceed sustained draw by a wide margin, which is part of why the headroom default is 30%.
- Connector count, rail layout, and cable gauge are not checked. A high enough wattage number does not guarantee the unit has the right connectors for your card.
Educational tool, not financial advice. Outputs are estimates from the inputs you supply and the assumptions above. See our editorial policy and disclosures.