calc.engineer / Homelab & Networking / Power Cost

Power Cost v1.0.0

Calculate total power consumption, electricity cost, and circuit requirements for a homelab. Enter each device's wattage to get daily/monthly/yearly kWh and cost at your local electricity rate. Accounts for cooling overhead via PUE (Power Usage Effectiveness). Shows amperage draw at 120V and 240V and warns if you exceed the NEC 80% continuous load limit on a 15A breaker. Essential for budgeting homelab operating expenses and ensuring your electrical panel can handle the load. Chain output total_watts into cooling_btu for heat load sizing.

feeds cooling_btu →
List of devices with their wattage
Hours per day the devices are running
Electricity cost in cents per kilowatt-hour
Power Usage Effectiveness — ratio of total facility power to IT equipment power. 1.0 means no cooling overhead, 1.2 is typical for a home server closet, 1.5+ for poorly ventilated spaces
Fill in the inputs and Compute to see the structured result.

From an agent (MCP) or the API

curl -X POST https://calc.engineer/api/power_cost \
  -H "Content-Type: application/json" \
  -d '{"devices": …, "hours_per_day": …, "kwh_rate_cents": …}'

MCP: connect to https://calc.engineer/mcp and call power_cost.

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