How do you compute non vat easily?

To compute a non-VAT amount easily, you can use the formula: Non-VAT Amount = Total Amount / (1 + VAT Rate). For example, if the total amount is $120 and the VAT rate is 20%, divide $120 by 1.20, which equals $100. This gives you the non-VAT amount. Adjust the VAT rate in the formula according to the applicable percentage.