Server Rack Power Density Calculator

Compute kW per rack by combining total IT load, redundancy headroom, and utilisation targets.

Sum of active IT power across the measurement window (kW)
Number of racks carrying load during the period
Optional: percentage headroom for N+1 or 2N designs (default 0%)
Optional: average utilisation you plan to run each rack at (default 100%)

Educational information, not a substitute for professional engineering design review.

Examples

  • Regional build: 360 kW load, 18 racks, 20% redundancy, 80% utilisation ⇒ 30.00 kW per rack
  • Edge pod: 96 kW load, 12 racks, 10% redundancy, 85% utilisation ⇒ 10.35 kW per rack

FAQ

What if I leave the optional fields blank?

Leaving redundancy or utilisation blank assumes 0% redundancy and 100% utilisation, yielding the direct load per populated rack.

Can I model future expansion?

Increase the redundancy margin to represent the extra headroom you require before adding more racks.

Does the result include cooling overhead?

No, the calculator focuses on IT power per rack. Combine the output with facility metrics such as power usage effectiveness to size upstream infrastructure.

How should I handle empty racks reserved for new gear?

Only count racks that are energised in the denominator. For empty racks, either exclude them or treat their load as part of the redundancy margin.

Additional Information

  • Result is expressed in kilowatts per rack.
  • Assumes uniform distribution of load across the counted racks.
  • Use with interval metering data to capture peak and average densities.
  • Does not account for power usage effectiveness (PUE); apply PUE separately if you need facility-level demand.

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