Add your components, set your duty cycle, enter your kWh rate (or pick a US state), and see the real cost of running your homelab 24/7.
For each component you add, we use a weighted average of its idle and load wattage based on the hours per day you specify. Total daily energy is converted to kWh, multiplied by your electricity rate, and projected to monthly, annual, and 5-year costs.
The CO₂ estimate uses the US grid average of approximately 0.37 kg CO₂ per kWh, which is a reasonable continental rough cut. If you're on a particularly clean grid (Pacific Northwest, Quebec) the real number is much lower; on a coal-heavy grid (parts of the Midwest) it's higher.
The "vs 8W baseline" comparison shows what you'd save by replacing your current setup with a tuned mini PC drawing 8W at idle — a realistic floor for a modern N100 or low-power Intel build running multiple services.
State preset rates are pulled from the most recent EIA residential averages and are updated periodically. They're useful as defaults but your actual rate (especially with tiered or time-of-use plans) may vary by 20% or more. Check a recent bill for the most accurate number.