 # Property Calculation – Understanding Accumulation Percent

When a Property is added with a Percent value, you can also calculate the total of the property in compositions using an ‘Accumulation Percent’ calculation.

Example – VOC Percent

A property VOCPC is added with a value type of Percent: The calculation tab shows this is required to be calculated for compositions, using the ‘Accumulation Percent’ method. The property based on is ‘VOCPC’ and the calculation source is ‘Physical Composition’: This means when determining the calculated result for a formulation:

1. the physical ingredients will be determined
2. the quantity of each physical ingredient will be collected plus the VOCPC property for each ingredient
3. the accumulation percent calculation will be performed
4. the calculated result will appear for the formulation

A simple formulation example follows, for Citral 10% DPG. The VOCPC has been entered for the physical raw materials of Citral and Dipropylene Glycol: The calculated result for VOCPC of the formulation is 10%.

The Maths of Accumulation Percent

The calculation works as follows:
Citral 10% DPG
Inputs=
90 parts DPG with VOCPC = 0%
10 parts Citral with VOCPC = 100%

Which means a formula total of 100 (as the above are percentages)

Calculation=
90 x 0 = 0
10 x 100 = 1000
Cumulative Total for formula = 0 + 1000 = 1000
Divide by the formula total to get to the percentage = 1000 / 100 = 10%

Example 2

Inputs=
20 parts RM1 with VOCPC = 0%
5 parts RM2 with VOCPC = 100%
20 parts RM3 with VOCPC = 100%
5 parts RM4 with VOCPC = 100%
Which means a formula total of 50

Calculation=
RM1 20 x 0 = 0
RM2 5 x 100 = 500
RM3 20 x 100 = 2000
RM4 5 x 100 = 500
Cumulative Total for formula = 0 + 500 + 2000 + 500 = 3000
Divide by the formula total to get to the percentage VOC in the formula
= 3000 / 50 = 60%