Self-hosted energy calculator

This self-hosted energy calculator adds up what your homelab really draws from the wall. Pick your hardware across four tiers, from a single Raspberry Pi to a stack of AI GPUs, set how many of each you run, and watch the totals update live: watts, monthly kWh, electricity cost, and yearly CO2.

$6.35/mo
43 W
total idle power
76 W
total load power
33.4 kWh
energy per month
154 kg
CO2 per year

Duty cycle

22 h idle + 2 h load per day, running 24/7

Electricity price

Monthly cost by country

Your setup at each country's average household price per kWh.

  1. Ireland$15.03
  2. Belgium$13.69
  3. Germany$13.69
  4. Italy$13.69
  5. United Kingdom$13.36
  6. Switzerland$12.36
  7. Denmark$12.02
  8. Austria$11.69
  9. Czechia$11.69
  10. Netherlands$9.69
  11. France$9.35
  12. Australia$8.68
  13. Spain$8.68
  14. Poland$8.02
  15. Portugal$8.02
  16. Sweden$8.02
  17. Japan$7.68
  18. Singapore$7.68
  19. New Zealand$7.01
  20. United States$6.35
  21. Finland$5.68
  22. Brazil$5.34
  23. Norway$5.34
  24. South Korea$4.34
  25. Canada$4.01
  26. Mexico$3.67
  27. China$2.67
  28. India$2.67

Compute

25 W
Raspberry Pi 4idle 3 W · load 7 WTom's Hardware, measured at wall
0
Raspberry Pi 5idle 3 W · load 10 WTom's Hardware, measured at wall
0
Mini PC (N100 class)idle 8 W · load 25 WServeTheHome N100 review
1
Tower server (Ryzen + 4 drives)idle 50 W · load 160 WCommunity builds, measured at wall
0
Rack server (Dell R730 class)idle 110 W · load 300 WDell community measurements
0

Storage / NAS

36 W
2-bay NAS (DS224+ class)idle 10 W · load 15 WSynology DS224+ spec sheet
0
4-bay NAS (DS923+ class)idle 25 W · load 36 WSynology DS923+ spec sheet
1
8-bay+ DIY NASidle 60 W · load 100 WUnraid community builds, measured
0

Network

15 W
Consumer router / modemidle 10 W · load 15 WMBReviews, measured
1
Managed switch, 8-portidle 5 W · load 8 WMBReviews, measured
0
Managed switch, 24-portidle 20 W · load 30 WMBReviews / FS specs
0
Wi-Fi 6/7 access pointidle 8 W · load 18 WMBReviews, measured
0

AI accelerators

0 W

Small edge

Coral USB / Hailo-8 / Pi AI HATidle 1 W · load 4 WSeeed / Hailo specs
0
Jetson Orin Nano / NXidle 5 W · load 20 WNVIDIA JetPack power modes
0

Consumer desktop GPU

NVIDIA RTX 5070idle 14 W · load 250 W250 W TGP spec; igor'sLab idle
0
NVIDIA RTX 5080idle 13 W · load 360 W360 W TGP spec; TechPowerUp idle
0
NVIDIA RTX 5090idle 30 W · load 575 W575 W TGP spec; TechPowerUp idle
0
AMD RX 9070 XTidle 10 W · load 304 W304 W TBP spec; igor'sLab idle
0
AMD RX 7900 XTXidle 20 W · load 355 W355 W TBP spec; TechPowerUp idle
0

Workstation GPU

NVIDIA RTX PRO 6000 Blackwellidle 30 W · load 600 W600 W spec; idle estimated
0
AMD Radeon PRO W7900idle 18 W · load 295 W295 W TBP spec; HotHardware
0

AI boxes with unified memory

NVIDIA DGX Sparkidle 35 W · load 200 WServeTheHome / Tom's Hardware
0
AMD Ryzen AI Max+ 395 mini PCidle 12 W · load 140 WServeTheHome MS-S1 Max review
0

Assumptions and sources

The estimate is deliberately simple: a flat price per kWh (no tiered or time-of-use tariffs), no PSU conversion losses, a 730 hour month, and no datacenter overheads like PUE or embodied carbon. Systems are counted as whole-box wall power; GPU cards are counted as card-only draw on top of a host system, at stock power limits. Real inference rigs often run power-limited, an RTX 3090 capped to about 275 W loses almost no tokens per second, so the load numbers here are the ceiling, not the floor. The duty cycle assumes your gear runs 24/7, idling most of the day; move the slider if your machines work harder. Measured wall numbers from a Kill-A-Watt or a smart plug always beat any preset.

Math

  • Daily kWh = (idle W × idle hours + load W × load hours) ÷ 1000
  • Monthly kWh = daily kWh, scaled to a 730 hour month
  • Cost = monthly kWh × your price per kWh
  • CO2 = yearly kWh × your grid intensity

Sources

  • Electricity prices: household averages in USD, Eurostat 2025.
  • Grid CO2 intensities: Ember.
  • Device wattages: the source under each row in the list.