Data Center Power Budget Calculator

Overhead is whatever total facility power (IT load × PUE) leaves over after subtracting IT load itself, and cooling is typically the largest single contributor to that overhead in a real facility. The 65% split is a typical-facility approximation used to estimate a cooling figure without requiring a separate mechanical-system input, but a site with free-air cooling or an unusually hot climate will have a cooling share that differs from this default.

UPS losses are computed directly from your UPS efficiency input as IT load × (1/efficiency − 1) — a real physical loss from AC-DC-AC conversion, unlike the cooling estimate which is just a share of the overhead PUE gap. PDU losses use the same formula with your PDU efficiency input, so both loss figures scale directly and independently from the equipment efficiency numbers you enter, not from the PUE assumption.

Total facility power is a fixed calculation from IT load × PUE regardless of how much of that provisioned capacity is actually being used. Cost per usable IT kW, however, divides monthly cost by effective IT power (IT load × capacity utilization), so a facility running well below its provisioned capacity shows a higher effective cost per kilowatt actually delivering compute — the same total bill spread over less useful output.

The CO2 figure uses a flat US-average grid factor of 0.42 kg per kWh applied to your annual energy consumption, which doesn't reflect your local utility's actual generation mix. A facility on a renewable-heavy grid will have meaningfully lower real emissions than this estimate, while one on a coal-heavy grid will have higher real emissions, so use this as a rough national benchmark rather than a site-specific carbon accounting figure.