Power Supply Calculator
Estimate your PC's total power draw by listing components and their wattage, then get a recommended PSU size with headroom.
Recommended PSU
Power Supply Sizing is straightforward — add up every component’s TDP (Thermal Design Power) or rated wattage, then add headroom so the PSU runs efficiently.
Total Draw = CPU + GPU + RAM + Storage + Fans + Other
Recommended PSU = Total Draw × 1.25 (25 % headroom)
Why headroom matters:
- PSUs are most efficient at 50–80 % load
- Transient spikes (especially modern GPUs) can exceed rated TDP by 50–100 W
- Leaves room for future upgrades
Typical component wattages:
- CPU: 65–125 W (up to 253 W for enthusiast chips)
- GPU: 75–350 W
- RAM (per stick): 3–5 W
- SSD: 2–5 W · HDD: 6–10 W
- Case fan: 1–3 W