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What a Megawatt Data Center Means, Size, Cost per MW and Equipment

A data center's MW rating is almost always its critical IT load, the power that reaches servers, not what the utility meter sees. Cushman and Wakefield puts all in US and Canada construction at about $17.6 million per MW in 2026, so a 20 MW site is roughly a $350 million project before chips.

Critical IT MW against total facility MW

When an operator says a building is 20 MW, it usually means 20 MW of critical IT load, the power the servers, storage and network gear can draw. Cooling, power conversion losses and lighting come on top. Power usage effectiveness, PUE, is total facility power divided by IT power, so the utility has to deliver the IT load times PUE. Utilities size the interconnection on the total draw. The Uptime Institute survey put the global average PUE at 1.54 in 2025, and hyperscale operators report about 1.10 to 1.15. Always ask which number a headline MW figure is, because the gap is 10 to 80 percent.

Critical IT load	Total draw at PUE 1.2	Total draw at PUE 1.54	Total draw at PUE 1.8
1 MW	1.2 MW	1.54 MW	1.8 MW
5 MW	6 MW	7.7 MW	9 MW
20 MW	24 MW	30.8 MW	36 MW
50 MW	60 MW	77 MW	90 MW
100 MW	120 MW	154 MW	180 MW

Computed as IT load times PUE. PUE 1.54 is the Uptime Institute 2025 global average as reported by mGrid. 1.2 and 1.8 are illustrative bounds for an efficient new build and an older site.

What a megawatt costs to build

Cushman and Wakefield's 2026 Data Center Development Cost Guide reports all in greenfield cost for the most modern US and Canada facilities at an average of $17.6 million per MW, excluding chips and GPUs, with a spread across markets from $8.9 million to $23.3 million. The firm says cost per MW is up 21 percent since its late 2024 edition, and that power infrastructure is the largest category at an average 21 percent of the total. JLL measures differently, shell and core only, and put the global average at $7.7 to $10.7 million per MW from 2020 to 2025, with $11.3 million forecast for 2026. The two series are not comparable, so compare like with like.

Critical IT load	Low, $8.9M per MW	Average, $17.6M per MW	High, $23.3M per MW
1 MW	$8.9 million	$17.6 million	$23.3 million
5 MW	$44.5 million	$88.0 million	$116 million
20 MW	$178 million	$352 million	$466 million
50 MW	$445 million	$880 million	$1.17 billion
100 MW	$890 million	$1.76 billion	$2.33 billion

Per MW figures from the Cushman and Wakefield 2026 Data Center Development Cost Guide and press release, US and Canada, all in greenfield, excluding chips and GPUs. Totals computed by multiplying.

Racks per MW depends on density

Racks per megawatt is 1,000 kW divided by the kW each rack draws. A traditional enterprise rack at 10 kW gives 100 racks per MW. An AI rack changes it sharply, because NVIDIA rates a GB200 NVL72 rack at about 120 kW, which needs liquid cooling and leaves only 8 or 9 racks per MW. Floor area per MW follows the same logic, so we do not quote a single square feet per MW figure. The honest answer is that the same megawatt fills a large hall at 10 kW a rack and a small one at 120 kW.

Critical IT load	Racks at 10 kW	Racks at 40 kW	Racks at 120 kW
1 MW	100	25	8
5 MW	500	125	42
20 MW	2,000	500	167
50 MW	5,000	1,250	417
100 MW	10,000	2,500	833

Computed as MW times 1,000 divided by kW per rack. The 120 kW rack is the NVIDIA GB200 NVL72 rating. 10 kW and 40 kW are illustrative densities.

Transformers and generators per MW

Every megawatt reaches the halls through transformers. The table sizes the plant for a site running at the 1.54 average PUE, a 0.95 power factor, unit substation transformers of 2,500 kVA and 2 MW generator sets, with no redundancy added. Real designs add spare capacity, so treat these as the minimum count and a starting point for a quote. A 2,500 kVA unit is a standard pad mounted size, see the 2500 kVA pad mounted transformer page. Above about 5 MVA the incoming feed is a substation transformer, and in 2026 Terrapin Construction Group listed substation transformers of 5 to 25 MVA at 65 to 95 weeks, so order them first.

Critical IT load	Total draw	Facility MVA	2,500 kVA transformers	2 MW generators	2.5 MW generators
5 MW	7.7 MW	8.1	4	3	2
20 MW	30.8 MW	32.4	13	10	8
50 MW	77.0 MW	81.1	33	25	20
100 MW	154.0 MW	162.1	65	50	40

Computed. Total draw is IT load times 1.54. MVA is total draw divided by 0.95. Transformer count is MVA times 1,000 divided by 2,500, rounded up. Generator counts are IT load divided by set size, rounded up, no redundancy. Generator output assumes the sets carry IT load only.

Reading 5, 20 and 100 MW

A 5 MW site is an edge or small enterprise facility, one utility feed at distribution voltage and a handful of pad mounted transformers. A 20 MW site is a colocation building, about $350 million at the Cushman and Wakefield average, and at PUE 1.54 it draws about 31 MW, which usually means a dedicated utility substation. A 100 MW site is a hyperscale campus at roughly $1.76 billion, drawing about 154 MW at the average PUE, with its own transmission voltage substation. For power use over time and cost of electricity, see the data center power consumption guide.

How much power a data center uses

Yearly energy, PUE and cost of electricity by facility size.

2500 kVA pad mounted transformer

The unit substation size used in the equipment table.

2 MW generators

Models, amps, fuel burn and lead times for 2000 kW sets.

Substation transformers

The utility feed transformer above about 5 MVA.

Transformer lead times

Why electrical gear is ordered first.

MVA transformers explained

kVA to MVA and where pad mount ends.

Common questions

What does MW mean for a data center

Megawatts of critical IT load, the power available to servers, storage and network equipment. Cooling and losses are extra, so the utility supply is the IT load times PUE.

How big is a 20 MW data center

At the 1.54 average PUE it draws about 31 MW from the utility. It holds about 2,000 racks at 10 kW or about 167 racks at 120 kW, and at the Cushman and Wakefield average costs roughly $350 million to build before chips.

What is the cost per MW to build a data center

Cushman and Wakefield reports an average of $17.6 million per MW all in for modern US and Canada facilities in 2026, with markets from $8.9 million to $23.3 million, excluding chips and GPUs. JLL's shell and core only figure is lower, $7.7 to $10.7 million globally from 2020 to 2025.

How many racks fit in one MW

1,000 kW divided by the rack power. That is 100 racks at 10 kW, 25 at 40 kW and about 8 at 120 kW.

How many transformers does a 20 MW data center need

At PUE 1.54 and 0.95 power factor the site is about 32.4 MVA, which is 13 transformers of 2,500 kVA before any spare capacity, plus the substation transformer for the utility feed.