Rack Power Budget Calculator

electrical

Calculates total IT power, cooling, PDU capacity, breaker sizing, rack U consumption, and weight for datacenter rack deployments. Supports predefined server platforms (DGX, HGX, etc.) or custom power/RU inputs.

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Server Platform

Predefined server platform name to look up from reference table (e.g., 'DGX H100', 'HGX B200', 'Dell R760xa'). If omitted, provide custom_server_power_kw instead.

Num Servers

Number of identical servers deployed in the rack. Typical: 1-4 for GPU servers (8U each), up to 20 for 2U compute nodes. If omitted, defaults to 1.

Custom Server Power Kw

Server power draw in kW when not using a predefined platform. Include all server components (CPUs, GPUs, memory, fans, PSU losses). Only required when server_platform is not provided.

Custom Server Ru

Rack units per server when using custom configuration. Standard servers: 1-4U; GPU servers: 4-10U. If omitted, defaults to 4U.

Custom Server Weight Kg

Weight per server in kg when using custom configuration. Used for raised floor loading checks. GPU servers: 30-100 kg. If omitted, defaults to 0 (weight check skipped).

Gpu Model

GPU accelerator model name for TDP lookup (e.g., 'H100 SXM', 'B200', 'MI300X'). Overrides the GPU model from the server platform if both are provided. If omitted, the GPU model from the server platform is used when available.

Pdu Model

PDU manufacturer and model for capacity validation (e.g., 'APC APDU10350SM'). If provided, checks whether the PDU can handle the total IT load at 80% continuous derating.

Voltage

Supply voltage in volts at the PDU/whip level. Common values: 208V (single-phase), 415V (international 3-phase), 480V (US 3-phase). If omitted, defaults to 480V.

Phases

Number of electrical phases for breaker sizing. Use 3 for three-phase (most datacenter feeds) or 1 for single-phase branch circuits. Standard: 1-phase for small racks (<5 kW), 3-phase for server racks (>5 kW). If omitted, defaults to 3 (three-phase).

Power Factor

Electrical power factor of the IT load. Modern server PSUs are typically 0.95-0.99 with active PFC. Use 0.9 for conservative sizing. If omitted, defaults to 0.9.

Rack Power Limit Kw

Maximum power capacity per rack in kW, set by facility electrical/cooling infrastructure. Typical enterprise: 10-20 kW; AI/HPC: 40-100+ kW. If omitted, defaults to 30 kW.

Include Networking Kw

Power budget for in-rack networking equipment (ToR switches, patch panels) in kW. Typical: 0.5-3 kW depending on switch count and port density. If omitted, defaults to 1.5 kW.

Include Switching Kw

Power budget for other in-rack ancillary equipment (KVM, management, sensors) in kW. Typical: 0.3-1.0 kW for top-of-rack switches, 0.5-2.0 kW for aggregation. If omitted, defaults to 0.5 kW.

Floor Area Sqft

Floor area allocated to this rack in square feet, used to compute power density in W/sqft. Typical hot aisle/cold aisle: 20-30 sqft per rack. If omitted, power density in W/sqft is not calculated.

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Reference data

This calculator pulls live values from the following engineering reference tables in the database.

gpu accelerator specs
server platform specs
pdu specs
rack infrastructure specs

About this calculator

Rack Power Budget Calculator is part of the Engineering Database calculator suite. Each tool runs deterministic calculations against authoritative reference data and code-compliant methods, so results are reproducible and traceable to source standards.

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