Website Carbon Calculator

Estimate the carbon emissions of website delivery and the effect of green hosting.

About Website Carbon Calculator

Website emissions follow directly from data transferred, energy intensity and the carbon intensity of the electricity used. Green hosting addresses only the hosting portion, not the network or device energy. Page weight reduction is the most effective lever because it reduces energy across the whole delivery chain rather than just the data centre.

Formula

Website Carbon

Emissions = data × energy intensity × grid carbon intensity

grid intensity: Carbon per kWh, which varies widely by hosting region
green hosting: Renewable-powered hosting reduces but does not eliminate emissions

Worked example

With the default values below, Website Carbon Calculator returns Annual Emissions of 1,794.62. 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 intensityminimum 0 kWh/GB: 0.81 kWh/GB
Grid carbon intensityminimum 0 kg/kWh: 0.44 kg/kWh
Share on renewable-powered hostingaccepts 0–100 %: 0 %

Results

Annual Emissions: 1,794.62 kg CO2e
Emissions per Pageview: 0.7478 g CO2e
Annual Data Transferred: 5,035.40 GB
Trees Needed to Offset Annually: 85.5
Saving From Green Hosting: 0.00 kg CO2e

Step by step

1Values used
2Website Carbon
3Annual Emissions= 1,794.62 kg CO2e
4Emissions per Pageview= 0.7478 g CO2e
5Annual Data Transferred= 5,035.40 GB
6Trees Needed to Offset Annually= 85.5
7Saving From Green Hosting= 0.00 kg CO2e

Assumptions and limits

The result is derived only from the 5 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 4 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 Carbon calculated?

Emissions = data × energy intensity × grid carbon intensity Website emissions follow directly from data transferred, energy intensity and the carbon intensity of the electricity used. Green hosting addresses only the hosting portion, not the network or device energy.

Why does Website Carbon matter?

Page weight reduction is the most effective lever because it reduces energy across the whole delivery chain rather than just the data centre.

What values do I need to enter?

This calculator takes 5 inputs: Monthly pageviews, Average page weight, Energy intensity, Grid carbon intensity, Share on renewable-powered hosting. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.