PC power, calculated honestly
Size your power supply, check your GPU’s power connector, and work out real UPS runtime — with transparent math, vendor-verified hardware figures, and the source linked on every card.
Power tools
The core of the site: PSU sizing, GPU power connectors, and UPS runtime. Each shows its formula, its assumptions, and where the numbers came from.
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.
Open toolGPU Power Connector Checker
Which power cables your graphics card needs.
Select a GPU to see its power connector requirement, estimated board power, a recommended PSU range, whether an ATX 3.x unit makes sense, and the cable safety notes that actually matter.
Open toolUPS Runtime & Sizing Calculator
How big a UPS, and how long will it actually last?
Add up your PC, monitor and network gear, then size a UPS and estimate real battery runtime. Accounts for inverter losses, Peukert capacity fade, battery age and the VA-vs-watts trap — and shows a range instead of a falsely precise minute figure.
Open toolMore utilities
Smaller calculators we keep around because they are useful and honest, even though they sit outside the power focus.
Why use Hardware Math
Transparent by default
Every result is an estimate, and we say so. We show the formula, the headroom we add, and the vendor figures we started from — no black boxes.
No ads, cookieless analytics
We measure traffic with cookieless, privacy-first analytics (Cloudflare Web Analytics) — no cookies, no cross-site tracking — and run no advertising. Your calculator inputs never leave your browser.
Original, not scraped
All illustrations are our own SVG artwork. We use no brand logos, no product photos, and we never invent an 'official' data source.
Built to be verified
Every GPU and CPU power figure is read from the manufacturer’s own specification page, and each one carries that source link and the date we checked it — so you can confirm any number here in one click. Where a vendor publishes no figure at all, the entry says so plainly instead of quietly filling the gap.
Data transparency
Core GPU and CPU power figures are verified against each vendor’s own official specification, with the source link and check date shown on every card — 163 of 164 entries. The one entry we could not confirm is named and flagged on its own page: where a manufacturer publishes no figure, we say so rather than filling the gap with an estimate. Every change is logged in the Data Changelog.
Hardware data last updated: 2026-07-22
View the Data Changelog →Safety & compliance in brief
Hardware Math is independent and not affiliated with any hardware brand. Results are estimates for planning, not electrical, engineering, or purchasing advice. Verify against official specifications and follow manufacturer safety guidance before building.
Read the full disclaimer →Where this is going
Hardware Math is built around one subject: PC power. The PSU calculator, GPU connector checker and UPS sizing tool are backed by per-GPU, per-CPU and GPU-plus-CPU reference pages, with eight in-depth guides behind them. Where this goes next: more vendor-verified GPU and CPU power data, model-specific sizing reasoning on each reference page rather than one generic recommendation, and guides covering the ATX and connector standards themselves. The monitor, download and electricity calculators stay available — they are useful, but they are not what this site is for. New languages will follow only after human review.
See the roadmap in the guides →Size your next build the honest way
Start with the PSU calculator — it takes about a minute and shows exactly how it reached its recommendation.
Start with the PSU Calculator