PUE Efficiency Calculator

Work out pue efficiency instantly with clear inputs, formula shown and shareable results.

About PUE Efficiency Calculator

PUE is total facility power divided by IT power, so 1.0 would mean every watt reaches the equipment. Hyperscale operators reach 1.1 with free cooling and containment; a typical enterprise computer room sits between 1.6 and 2.0, meaning as much energy goes on cooling and losses as on computing. Improving PUE is pure operating cost reduction.

Formula

PUE

PUE = total facility power / IT equipment power; overhead = total - IT; saving at target = (current total - IT x target PUE) x hours x price

Worked example

With the default values below, PUE Efficiency Calculator returns Power usage effectiveness of 1.444. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total facility powerminimum 0.1 kW: 260 kW
IT equipment powerminimum 0.1 kW: 180 kW
Electricity price per kWhminimum 0: 0.18
Target PUEaccepts 1–4: 1.3

Results

Power usage effectiveness: 1.444
Non-IT facility power: 80.0 kW
Annual saving at the target PUE: $41,025
Efficiency rating: Good - modern facility

Step by step

1Values used
2PUE
3Power usage effectiveness= 1.444
4Non-IT facility power= 80.0 kW
5Annual saving at the target PUE= 41,025
6Efficiency rating= Good - modern facility

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Can PUE be below 1?

No, not by definition. Facilities that reuse waste heat report a separate metric, ERE, which can fall below 1 because exported heat is credited.

Does a low PUE mean an efficient data centre?

Not necessarily. PUE improves when IT load rises even if that load is doing nothing useful, so it must be read alongside utilisation and work-per-watt measures.