# Calculating field while dissolving in ArcMap

I have two polygon Layers, A and B correspondingly. The polygons of B are lying on top of layer A and also overlapping the polygons of A (I made an example of the attribute table for better understandings).

I want to keep track of how much percentage of polygon A has `"value_1"` in different categories in it (`"value_1"` is originally from polygon B).

Example. Let's say my attribute table looks like this:

``````A_ID  B_ID  area_a  area_b  %area  value_1
1      1     100     30       30     2
1      2     100     45       45     5
1      3     100     25       25     16

2      4     50      10       20     12
2      5     50      30       60     5
2      6     50      10       20     5
``````

The Output should look like this:

``````ID_A  area_a  value_1 <10  value_1 <20
1       100     75%            25%
2       50      80%            20%
``````

I guess I have to dissolve `"A_ID"` but I don't know how to calculate the field `'value1_ < 10' and 'value1_ < 20'` while dissolving. Any suggestions?

• Hi, i dont have the license for doing this, so i tried the approach from @Keagan Allan. That worked for me. But thank you very much! Sep 5, 2019 at 14:32