Rack Power Calculator
The rack power calculator estimates the electrical and thermal load of your rack equipment. Enter the number of devices per rack, their average power draw, the number of racks, and how many power feeds each rack has.
In return you get the watts per rack, total watts across all racks, the equivalent BTU/hr and tons of cooling required, the expected current draw at 120V and 240V, and the watts that must be carried by each feed. It is the quickest way to check whether a rack, PDU, or circuit is undersized before you fill it with gear.
Rack Power Calculator
Calculate total rack power consumption, BTU, and amperage across feeds.
Enter values above to see results.
Frequently Asked Questions
How many amps does my rack draw?
Divide the total wattage by the voltage: watts / 120 for 120V circuits and watts / 240 for 240V circuits. For a balanced 3-phase feed, divide further by the number of phases.
How do I convert watts to BTU and tons of cooling?
One watt of electrical load produces about 3.412 BTU per hour. To size cooling, divide the total BTU/hr by 12,000 to get tons of cooling (1 ton = 12,000 BTU/hr).
Read More
Guides that go deeper on the same topic.
Rack Power Budgeting: kW per Cabinet, PDU Types, and A/B Feeds
Budget rack power with confidence: what kW per cabinet really means, which PDU type to choose, and how A/B redundant feeds should be sized, metered, and documented.
Rack Capacity Planning: A Practical Guide to Power, Space, and Resource Forecasting
A practical guide to rack capacity planning covering power budgeting, space utilization, cooling constraints, and how to forecast physical resources before deployments create crises.
Data Center Rack Layout Best Practices: Power, Cooling, and Space Planning
A practical guide to data center rack layout covering rack selection, power distribution, cooling strategies, space planning, cable management, and common mistakes to avoid.
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