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Rack Capacity

Build your rack equipment by equipment and instantly get the used U, the power, the thermal dissipation (BTU/h), the weight and the current you will need. All the calculation happens in your browser.

Presets 24U · 42U · 45U · 48U or type a value.

Rack equipment

Enter height in U, quantity, draw in W each and weight in kg each per equipment.

redzilla.cl — rack
 

Space occupancy

0U of 0U 0%
Used U
0U
of 0U total
Free U
0U
available space
Power
0 kW
0 W
Dissipation
0 BTU/h
thermal load
Total weight
0 kg
loaded equipment
Current
0 A
at 220 V
Summary by equipment
Equipment U each Qty Total U Total W Total kg
Total

Current estimated at 220 V (standard in Chile: 220 V / 50 Hz). Dissipation uses 1 W = 3.412 BTU/h. Consider a safety margin and the actual cooling of your room.

Runs locally in your browser · no sign-up · nothing leaves your browser

How it works

The calculator builds a rack inventory device by device (height in U, quantity, power in W and weight in kg per unit) and totals four dimensions at once: space (used U = Σ U × quantity, against 24, 42, 45, 48 or any size you define, up to 60U), total power in W and kW, total weight and estimated current at 220 V (A = W / 220, the 220 V / 50 Hz standard used in Chile).

It also converts electrical consumption into heat load with the factor 1 W = 3.412 BTU/h: practically all the energy the equipment draws ends up as heat the air conditioning must remove. The occupancy meter warns when the rack passes 85 % and turns red when the equipment does not fit (used U greater than the total).

Example: 42U rack with a switch, patch panels, servers and a UPS

  1. Space: 1 switch (1U) + 2 patch panels (1U each) + 2 servers (2U each) + 1 UPS (2U) = 9U used, leaving 33U free (21 %).
  2. Power: 65 + 0 + 2×450 + 300 = 1265 W1.27 kW.
  3. Heat: 1265 × 3.412 ≈ 4316 BTU/h to be removed.
  4. Current: 1265 / 220 ≈ 5.8 A, and total weight adds up to 67 kg.

Frequently asked questions

How many U does a standard rack have and how tall is one U?
One rack unit (U) is 44.45 mm (1.75 inches) tall, per the EIA-310 standard. The most common racks are 42U (~1.87 m of equipment), with 24U cabinets for offices and 45U or 48U for datacenters also widely available.
How do I convert rack watts to BTU/h?
Multiply by 3.412: a rack drawing 1000 W dissipates about 3412 BTU/h. Nearly 100 % of the electrical power turns into heat, so the air conditioning must be sized to remove the combined consumption of all the equipment.
Should I fill the rack to 100 %?
No. It is recommended to keep 15 % to 30 % of the U free for growth, cable managers and airflow; that is why the tool warns from 85 % occupancy. A packed rack complicates maintenance and worsens cooling.
Is my rack data sent to any server?
No. All the math runs in your browser: the equipment inventory, power draws and weights never leave your machine, so you can use it with internal infrastructure information without exposing it.
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Disclaimer We take great care to keep every tool accurate and review it thoroughly; even so, we can't guarantee it is free of errors or take responsibility for how the results are used. We recommend double-checking anything critical.
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