This is actually simpler than you might think.
First, you need to know the widths of your units, for example, if you have 2x 600 base units, 1x 600 appliance unit, 1x 1000 sink unit & 2x 500 drawer packs, this works out as follows:
600 + 600 + 600 + 1000 + 500 + 500 = 3800mm
Next you need to work out if you have any 'returns' - a return is at the end of your run of units which goes from the front of the cabinet to the back wall. However, if you select to have full height end panels on your last cabinet, there is no need to continue the plinth or pelmet around the corner. This is because the plinth or pelmet butts up to the end panel. In most cases you will have returns for cornice.
If you do have returns we recommend a width of 600mm is used for each of these.
Therefore, to calculate the total for each plinth, pelmet or cornice use the example sum as follows:
Unit width + any returns (600mm for each) = total length
e.g. 3800mm + 600mm = 4400mm
To calculate the number of lengths you require you will need to see which lengths are available in your preferred kitchen range. For example, our plinths come in 2600mm, 2750mm or 3000mm lengths
So taking our example above with a range using 3000mm plinths the calculation is:
Total length (4400mm) divided by Plinth Length (3000mm) = 1.46
Therefore, the requirement in this example is 2 lengths. Simple!