Get the app
Windows 10 / 11 Free — Pro included 17 languages

A real-time power consumption monitor for Windows PCs

Your PC is on the electricity bill. Now you can read the line item.

PCWattVault is a free Windows app that shows your PC’s power usage and electricity cost in real time — live watts measured from your own hardware, priced with your own tariff (night rates and tiers included, and your country’s plan as a starting template), and recorded in the background so the history never has holes.

Get it on the Microsoft Store Free download Read the guide
No accountNo cloudNo telemetryMIT-licensed code
Live demo SIM · demo tariff €0.19/kWh
Current draw
278W
measured at the wall (smart plug)
Cost rate
€0.053/h
standard tariff
Today
€0.17
894.7 Wh
This month
€2.91
15.32 kWh
Month-end
€30.08
158 kWh
At current draw — if it ran 24/7
€0.053per hour
€1.267per day
€8.87per week
€38.01per month
Live wall power 5m30m1h6h24h
400 W300 W200 W100 W0 W
-300s-150s0s
Where the watts go
CPU GPU Memory Storage Base load PSU loss
Simulated preview of the real dashboard — your figures come from your own hardware.
Since you
opened this page
00:00elapsed
0.000kWh
€0.000spent
At a simulated draw. A real 300 W gaming PC costs roughly €1.37 per 24 h at €0.19/kWh.
01 — MEASURE

Six answers your power bill never gives you

Everything below runs locally, updates every second, and keeps working while the window is closed in the tray — because a history with holes is worth nothing. The tray icon itself shows the live watts.

PCWattVault — Dashboard Actual app
The PCWattVault dashboard: 278 W current draw measured at the wall, cost rate per hour, today and this month in euros, a month-end forecast, a live wall-power chart over the last five minutes, and a donut breaking down where the watts go between CPU, GPU, memory, storage, base load and PSU loss.
Live dashboard — real hardware, real tariff, recorded continuously in the background.
Right now

Wall power, not guesswork

Component sensors plus base load, divided by your PSU efficiency — or a real reading: a smart plug measuring at the wall, or a Corsair HXi/RMi or MSI MEG Ai power supply reporting its own power over USB. No plug needed for a sound estimate: it is fitted to your hardware — drives by type, memory per module, base load from the board. The line under the figure always tells you which one you are looking at.

GPUCPUDrivesBase + PSU loss
Per device

Every consumer, ranked live

Two GPUs? Each appears separately with its own draw. CPU, drives, everything with a sensor of its own — ranked in real time. A “~” marks anything the app estimated rather than measured, so you always know how solid a number is.

RTX 3090248 W
Ryzen 9104 W
NVMe~8 W
History

Hourly, daily, monthly — forever

Today by the hour, 30 days, 12 months, lifetime totals — in kWh or in money, with a per-component breakdown. Hover a bar to see what made it: its top components and apps.

Tariff engine

Priced the way you are billed

Time-of-use windows, weekday and seasonal rules, consumption tiers with a household baseline, solar hours, demand charges. Any currency.

23–07 NIGHT 07–17 DAY 17–23 PEAK
Ahead of time

Forecast & predictions

Where this month will land, and — after ten recorded days — next month and next year as honest ranges, not fake precision.

€24
€31
Laptops

Battery time left and healthNew in 1.0.18

Power measured from the battery itself, time left at the current draw, and battery health. Health is how much the battery holds when full, against what it was designed for; on the charger, the card shows the charge and the health. Free, and shown only on PCs that have a battery.

02 — PER APP

See which apps cost you money

The Apps page splits your PC’s measured power between the programs using it — live, per day, and against the days before. It is a Pro feature, free for early adopters like every Pro feature.

PCWattVault — Apps Actual app
The PCWattVault Apps page in the Now view: each app's estimated watts and cost per hour, with an Other apps row and a System baseline row that together add up to the measured total.
The Now view — each app’s estimated share of the measured total, and what it costs per hour.
Right now

Every app’s watts and cost per hour

The 12 apps drawing the most get a row each, with their estimated watts and cost per hour — windowed or not; ones without a window are tagged “background”. Everything smaller, and any app you hide, is summed as “Other apps”, and a “System baseline” row covers what you pay whatever runs: every part’s idle draw, the base load and the power supply’s loss. The rows add up to the measured total.

AppsOther appsSystem baseline
= the measured total · illustration
How it works

An honest split of a measured total

PCWattVault measures the total — from the hardware sensors, or at the wall with a Tapo smart plug. Only the power above each component’s idle draw is shared between apps, by their share of CPU and GPU time from Windows’ own per-process counters, every 5 seconds. No other process is opened or read. It is an estimate, not a per-app meter — and until the idle draw has been learnt, the page says it is still learning.

Per day

Each app’s daily cost

Today, Last 7 days and Last 30 days — up to 25 apps each, recorded on your PC only. Click an app to see its cost per day over the last 30 days.

Compared

Up or down, and by how much

The 7- and 30-day views compare each app with the same number of days before them.

Spikes

A spike explains itself

Hover the live chart and it names the three apps drawing most at that moment. The dashboard shows the three biggest right now in one line under its cards, with “All apps →”.

Alerts

Per-app alerts

“App power above N W”, averaged over 1–120 minutes (default 5) so a momentary spike does not count, and “App's cost today above X”. Or open an app and press “Alert me about this app”.

Your call

Hide what you would rather not keep

“Hide” on an app’s row counts it under “Other apps” from then on and removes its name from everything already saved. Switch the app history off, or clear it — your total consumption history is not touched. Nothing about which apps ran leaves your PC.

03 — CALIBRATE

The feature that makes the numbers honest

Most tools stop at “here is an estimate”. PCWattVault lets a real measurement teach the estimate — once — and then keeps being accurate even after you take the meter away.

  1. Plug the PC into a Tapo P110/P115Whatever sits on the plug is what gets measured — so put only the PC on it. Or use a Corsair HXi/RMi or MSI MEG Ai power supply: it reports its own power over USB.
  2. The dashboard switches to “measured at the wall”History and costs are now recorded from the real reading. If the plug drops off Wi-Fi, the software model takes over within seconds — no hole, no frozen number.
  3. A calibration bar appearsMeasured vs model, and the average gap over the last few minutes. Do it at your normal desktop load, not mid-benchmark.
  4. One click folds the gap into your base loadThat is the whole point: the model itself becomes honest. Your figures stay realistic when the plug is offline — or even if you remove it for good.
Calibration · last 5 min
Measured — Tapo P110312 W
Software model276 W
Average gap+36 W
↺ Tune base load by +36 W

A large gap is not a bug — it usually means fans, pumps, RGB and USB gear were under-counted. Which is exactly what the button fixes.

04 — KEEP

An app that measures your electricity has no business phoning home

PCWattVault is local-first in the strict sense: there is no account to create, no server to sync with, and the interface is physically prevented from making network requests.

0

Accounts, sign-ups and cloud services. The app works the second it opens.

0

Telemetry, analytics and crash reporting. Nothing is collected — not even anonymously.

JSON

Your history is plain readable files in your own profile, and an automatic backup, kept outside the app’s folder, survives an uninstall.

Proof, not a promise

You do not have to take “no telemetry” on trust. The app’s interface is not merely asked to stay offline — it is blocked from going online, by the security policy the app enforces on itself:

Content-Security-Policy: connect-src 'none'

Raw per-second samples are never written to disk — only hourly aggregates per component category and, with power per app, daily totals per app — so nobody can reconstruct your minute-by-minute activity from the files. Which apps ran never leaves your PC. Smart-plug credentials, if you use that feature, are encrypted with Windows DPAPI and are used only to talk to the plug on your own network. Read the full inventory →

05 — EXTRAS

Pro features, and the promise attached to them

The free app is complete: tariffs, history, forecasts, predictions, themes, 17 languages. Pro adds the things you ask for once you have lived with the data for a while.

Power per appNew in 1.0.15

Which apps your PC’s power goes to — live, per day, and compared with the days before — with the three biggest right under the dashboard’s cards and in the live chart’s tooltip. An estimate: the measured total, split by each app’s share of CPU and GPU time.

AlertsNew in 1.0.22

Windows notifications when temperature, wall power or the daily cost crosses your thresholds — and per app: an app’s power, averaged over minutes, or its cost today. And a monthly budget or CO₂ limit: one warning when the month-end forecast passes it, one when the month reaches it, and a short note when a month stayed under it. Anti-spam built in.

Sessions

“What did that gaming night / render / training run cost?” Every session records kWh, cost, peak and average watts.

Reports & export

Excel-friendly CSV and a monthly PDF with charts, tariff summary, predictions and a CO₂ line.

Smart plug

Connect a Tapo P110/P115 and your history is recorded from real wall measurements instead of a model.

Founder
license

Right now, every Pro feature is free — and that is a promise, not a trial. While PCWattVault is young, each installation records a Founder / Early-Adopter marker. The Microsoft Store keeps the record too, so when you are signed in to the Store, your founder status follows your Microsoft account to any PC. If Pro ever becomes a paid upgrade for new users, installations carrying the marker keep everything at no cost, forever. Nothing to claim: yours is already under Settings → PCWattVault Pro.

06 — INSTALL

Install in one click. Go full depth in a few minutes.

PCWattVault ships through the Microsoft Store — sandboxed, auto-updated, and removed cleanly if you ever uninstall, except the founder marker and the history backup, which stay in %USERPROFILE%\.pcwattvault on purpose. Out of the box it measures GPU power directly and estimates the CPU; pair it with one free tool and every sensor becomes a real measurement.

Microsoft Store

Free

Install, done. Sandboxed and updated by Windows.

  • One-click install and automatic updates
  • The full app: tariffs, history, forecasts, sessions, reports — every Pro feature free for early adopters, forever
  • GPU power measured directly from day one
  • No account, no telemetry — nothing ever leaves your machine
  • CPU power is estimated (“~”) until a sensor source provides it — see the next card
Open in the Store

Full sensor depth

Optional power-up

Want measured CPU power, temperatures and fan speeds instead of estimates? Pair PCWattVault with the free, open-source LibreHardwareMonitor.

  • Download LibreHardwareMonitor from its official release page on GitHub — LibreHardwareMonitor.zip suits most PCs; LibreHardwareMonitor.NET.10.zip needs Microsoft’s .NET 10 runtime
  • Unzip it and run it as administrator — if it offers to install the PawnIO driver it needs, accept
  • Flip one switch: Options → Remote Web Server
  • PCWattVault detects it and switches automatically within seconds — the “~” marks disappear
  • Close it any time: PCWattVault hands back to its estimates seamlessly, your history never skips a beat
Download LibreHardwareMonitor only from its official GitHub page. Some other websites use the LibreHardwareMonitor name without being part of the project, and what they offer may not be the genuine program. The LibreHardwareMonitor developers warn about this themselves. The same goes for the PawnIO driver: take it only from pawnio.eu or through LibreHardwareMonitor’s own driver prompt.
See how, step by step
07 — ASKED

Before you install

Why does the CPU show “~” or 0 W?

Reading real CPU package power on modern Windows needs a driver-backed sensor source. Install the free LibreHardwareMonitor — only from its official release page on GitHub, since other websites use its name without being part of the project — run it as administrator, and turn on Options → Remote Web Server; PCWattVault picks it up within seconds and the tildes disappear. Until then it estimates CPU power from load, which is exactly what the “~” is telling you. GPU power is measured directly either way.

Does it work on laptops?

Yes. On battery, PCWattVault reads the laptop’s power draw from the battery itself (since version 1.0.10), and the dashboard marks it “measured from the battery” — a measurement, not a model. From version 1.0.18, a card at the top of the dashboard also shows the time left at the current draw and the battery’s health. On the charger, the total is an estimate again: LibreHardwareMonitor makes the CPU and GPU readings more precise, but only a smart plug measures the laptop at the wall. From version 1.0.20 that estimate starts from laptop defaults and calibrates itself from the battery after 10 minutes on battery. More in How much power does my laptop use?

The app doesn’t close when I close the window.

By design. It keeps recording in the background, because a history with gaps is useless. To stop it: right-click the tray icon → Quit. Whether closing the window hides it into the tray is a separate choice — Settings → Behaviour → Hide to the tray when the window is closed — and recording continues either way.

Can I see the watts without opening the app?

Yes. From version 1.0.19 the tray icon shows the live wall watts as white digits on a dark navy plate, refreshed every 2 seconds; hovering over it shows the watts and the cost per hour. If Windows keeps the icon behind the ^ arrow next to the clock, drag it onto the taskbar. It is on by default — Settings → Behaviour → Show the live watts on the tray icon turns it off.

What is the yellow “Demo data” banner?

It means no real sensor source could be reached, so the app is showing synthetic numbers to keep the interface alive and explorable. Demo data is never written to your history.

My NVMe temperature differs from the vendor tool.

PCWattVault shows the official composite sensor — the same one Samsung Magician and similar tools display. Some utilities show the controller hotspot instead, which legitimately runs 20–30 °C hotter.

Are sleep and hibernation billed?

Never. Gaps in time are detected and excluded from the energy integration, so a weekend of sleep does not silently become kilowatt-hours.

Do I have to give the app my TP-Link password?

Only if you use the optional smart-plug feature — that is how Tapo authenticates apps on your own network. The credentials are stored encrypted with Windows DPAPI, are used solely for the local handshake with the plug, and are never sent to the internet. “Clear credentials” deletes them immediately.

Find out what your PC has been quietly adding to the bill.

Get it on the Microsoft Store Free download Read the guide

These are estimates. Every figure PCWattVault shows — watts, energy, costs, forecasts, predictions, CO₂ — is intended for guidance. Even a smart plug or digital PSU is a consumer-grade measurement. Your utility’s certified meter and your contract are the only authority for what you actually pay: do not use these figures for billing, for splitting costs between people, or for financial decisions.

Independence. PCWattVault is an independent application with no affiliation, endorsement or commercial relationship with TP-Link. TP-Link and Tapo are trademarks of their owner; the optional smart-plug feature uses the plug’s local device interface on a best-effort basis. LibreHardwareMonitor and PawnIO are third-party open-source projects with their own licenses.