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percentagefinance

Calculate tax value from gross and tax percentage


I need to calculate the actual tax value when only the gross value and tax percentage is known.

The basic formula to calculate the gross amount:

Gross = Net * 1+Vat
Tax = Net * Vat

Example:
Net = 152.75 USD
Vat = 7 %

Gross = 152.75 * 1.07 = 163.44 USD
Tax = 152.75 * 0.07 = 10.69 USD

Proof: 
Gross - Tax = Net
163.44 USD - 10.69 USD = 152.75 USD

However, in my case I only have Gross and Vat and need to get the Tax value in a single multiplication.

The current approach is the following:

Tax = Gross − (Gross / 1+Vat)

Example:
Tax = 163.44 USD - (163.44 USD / 1.07) = 10.69 USD

Question:

How can I get the Tax value with a simple multiplication, without the need of a subtraction.


Solution

  • The answer, posted in the comment by @PranavanSp:

    Gross to Tax

    Tax = Gross * Vat / (1 + Vat)

    Example:
    Tax = 163.44 * 0.07 / 1.07 = 10.69


    Gross to Net

    And for completeness, also the net calculation:

    Net = Gross / (1 + Vat)

    Example:
    Net = 163.44 / 1.07 = 152.75