# Notes on calculating the average Envirometer

When calculating the average, the following methods are applied:

Standard calculation rules:

If you select the standard calculation rules, the system does not take into account whether or not the data have been filled in (completely). All data are included:

• An item that has not been filled in is counted as zero.
• Input fields with '0' are counted as zero.
• You can choose wheter or not to include fields marked with 'Priliminary data'.

If you select the advanced calculation rules, this means that:

• if a value has been entered > the value is included, except when the box ‘preliminary data’ in the left margin has been ticked.
• if no value has been entered > the value is not included.
• if the value is set at null > the value is included in the average.
• if the item has been hidden via finetuning > the data are not applicable and are not included in the average.

You can select normal/ FTE/ turnover/ production. If you mean to apply the standard calculation rules, we advise that you select the ‘normal’ method. With the advanced calculation rules, every method (FTE/ turnover/ production) will yield different results. Below you will find how these averaging methods work, followed by an example for clarification.

• normal:
• For every item (for instance m2 floor area or company waste in kilograms) all data that are included in accordance with the calculation rules selected (see above) are added up.
• The sum is divided by the total number of data included.
• FTE (or turnover or production):
• For every item, all data that are included in accordance with the calculation rules selected are added up.
• For every item, the total is divided by the total number of FTE (or turnover or production) that are included in the data used in accordance with the calculation rules.

Example using the advanced calculation rules

Below you will find the calculation of the average of three companies for a number of environmental items, using the calculation rules:

• normal
• per FTE
 A B C normal FTE employees (FTE) 5 6 4 (5+6+4)/3 = 5 (5+6+4)/(5+6+4) = 1 floor area (m2) 100 180 200 (100+180+200)/3=160 (100+180+200)/(5+6+4) = 32 electricity (kWh) 3000 not filled in 5000 (3000+5000)/2 = 4000 (3000+5000)/(5+4) = 889 glass waste (kg) 75 150 not filled in (75+150)/2 = 113 (75+150)/(5+6) = 20

The results seem very different. That is because the FTE-method is scaled to a company with 1 FTE. The FTE numbers are therefore about a factor 5 lower than the ‘normal’ numbers. It shows that a chart of an FTE-average Envirometer only makes sense if you can compare it with the chart ‘per employee’.

The next table shows the different key indicators yielded by the two methods applied in this example. It shows that if all data are complete, the calculation methods yield the same results, although the results are affected if data are lacking (and showing the ‘to be completed’ status) from one or more the companies.

 key indicator normal FTE electricity/floor area (kWh/m2) 25 28 glass waste/employee (kg/FTE) 22,5 20 floor area/employee (m2/FTE) 32 32