Hi
HKiran,
I try to create a table based on your description.

Then I create a query to calculate data.
SELECT
qty*rate as AccessAmount,
AccessAmount-discount as TaxableValue,
TaxableValue*1/100 as Tax_1_Amount,
TaxableValue*2/100 as Tax_2_Amount,
TaxableValue*3/100 as Tax_3_Amount,
TaxableValue + Tax_1_Amount + Tax_2_Amount + Tax_3_Amount as SubTotal
from product_data;
Output:

Then I try to create a Form. Now I have a confusion that your form shows data in Datasheet view or in Form View?
If you are displaying in Datasheet view then you can add Total like below.

You can add Totals like above from 'Totals' option in Home Tab.

If you are displaying the form in Form View like below.

Can you confirm, Which Total you want to display in textbox for Total?
If possible you can show us the picture of your desired output.
We will try to provide you suggestions to achieve that.
Regards
Deepak
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