Website Energy Use Calculator

Estimate the energy consumption of website delivery.

About Website Energy Use Calculator

Energy consumption is proportional to data transferred, so page weight reduction cuts energy directly. The commonly used intensity figure covers data centre, network and device energy combined. Halving page weight halves delivery energy, which makes performance optimisation and sustainability the same work.

Formula

Website Energy Use

Energy = data transferred × energy intensity per gigabyte

energy intensity: About 0.81 kWh per GB across the full delivery chain

Worked example

With the default values below, Website Energy Use Calculator returns Annual Energy Use of 4,078.67. Change any input above and every figure here is recalculated in your browser.

Inputs used

Monthly pageviewsminimum 0: 200,000
Average page weightminimum 0 KB: 2,200 KB
Energy intensity of data transferminimum 0 kWh/GB: 0.81 kWh/GB
Energy price per kWhminimum 0: 0.15

Results

Annual Energy Use: 4,078.67 kWh
Monthly Energy Use: 339.890 kWh
Monthly Data Transferred: 419.617 GB
Annual Energy Cost: $611.80
Energy per Pageview: 1.69945 Wh

Step by step

1Values used
2Website Energy Use
3Annual Energy Use= 4,078.67 kWh
4Monthly Energy Use= 339.890 kWh
5Monthly Data Transferred= 419.617 GB
6Annual Energy Cost= 611.80
7Energy per Pageview= 1.69945 Wh

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 5 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

How is Website Energy Use calculated?

Energy = data transferred × energy intensity per gigabyte Energy consumption is proportional to data transferred, so page weight reduction cuts energy directly. The commonly used intensity figure covers data centre, network and device energy combined.

Why does Website Energy Use matter?

Halving page weight halves delivery energy, which makes performance optimisation and sustainability the same work.

What values do I need to enter?

This calculator takes 4 inputs: Monthly pageviews, Average page weight, Energy intensity of data transfer, Energy price per kWh. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.