What is the formula to work out VAT backwards?

Asked by: Cecilia Mante  |  Last update: June 27, 2026
Score: 4.1/5 (48 votes)

To work out VAT backwards (remove VAT from a gross amount), divide the gross price by 1 + ( VAT rate as a decimal ) 1 + ( V A T r a t e a s a d e c i m a l ) . For a 20% rate, divide by 1.2.

How to reverse 20% VAT?

To work out 20% VAT backwards, divide the price that includes VAT by 1.2. This gives you the price before VAT was added. For example, £120 including VAT divided by 1.2 equals £100 – the original price without VAT.

How do you take 20% VAT off a price?

You can calculate the total price excluding the standard VAT rate (20%) by dividing the original price by 1.2. To work out the reduced VAT rate (5%), divide the original price by 1.05.

How do I work out VAT backwards?

To remove Value Added Tax or to make a reverse VAT calculation the formula is the following: Net: (Amount / 120) * 100 Easy! Divide the amount by 100 + VAT% and then multiply by 100. That's the amount excluding VAT taxes (Net amount).

How to do reverse calculation formula?

How to use reverse percentages given a percentage of an amount (calculator method)

  1. Write down the percentage and put it equal to the amount you have been given.
  2. Divide both sides by the percentage. (e.g. if you have 80% , divide both by 80 ). This will give you 1% .
  3. Multiply both sides by 100 . This will give you 100% .

How to calculate VAT - Simple Method VAT Calculation

35 related questions found

How do I work out GST backwards?

Subtracting GST:

To calculate how much GST is included in a price, just divide by 11. To calculate how much the price was before GST, just divide by 1.1.

How to reverse 20% tax?

Subtracting VAT from a Price

  1. If you know the VAT rate, divide the gross amount by (1 + VAT Rate).
  2. Formula: Net Amount = Gross Amount / (1 + VAT Rate).
  3. Example: If the gross amount is £120 and the VAT rate is 20%, then Net Amount = £120 / 1.20 = £100.

What is a reverse VAT calculator?

The calculator will take the gross amount and will estimate the net amount and VAT based on the VAT rate you input. The reason it is called a reverse calculator is that when it is given the gross (total) amount, it works backwards to deliver the net and VAT amounts.

Is a reverse tax calculator free to use?

Reverse Sales Tax Calculator - Calculate Original Price Before Tax | Free Tool.

Why do you divide by 1.2 for VAT?

Net price = Gross price ÷ (1 + VAT rate)

In the UK, the standard VAT rate is 20%, so you'd divide by 1.2. For example, say something costs £120 including VAT. To find the price excluding VAT: £120 ÷ 1.2 = £100 (which means £20 is the VAT).

What is the reverse VAT rule?

The reverse charge mechanism is a tax collection method used in value-added tax (VAT) systems. It shifts the responsibility of reporting and paying the VAT from the seller (supplier) to the buyer (recipient) of the goods or services.

How to calculate a percentage backwards?

To do reverse percentages, find the original amount by first determining what percentage the given number represents (e.g., 100% - 20% discount = 80%), then divide the given number by that percentage to find 1%, and finally multiply by 100 to get the original total, or use the multiplier method: divide the final value by its decimal multiplier (e.g., 0.80 for an 80% value). 

What's the formula for reverse GST calculation?

Firstly, divide the GST-inclusive price by (1 + (GST rate/100)) to determine the base price. Lastly, subtract this value from the total price. Yes, you can use the reverse GST calculator for all GST types—CGST, SGST, and IGST.

How do you calculate tax backwards?

What is a Sales Tax Decalculator?

  1. Step 1: take the total price and divide it by one plus the tax rate.
  2. Step 2: multiply the result from step one by the tax rate to get the dollars of tax.
  3. Step 3: subtract the dollars of tax from step 2 from the total price.
  4. Pre-Tax Price = TP – [(TP / (1 + r) x r]
  5. TP = Total Price.

Why do we divide by 11 to get GST?

GST (Goods and Services Tax) is a 10% tax applied to most goods and services sold in Australia. Think of it as the government's slice of the pie—exactly one-eleventh (1/11th) of the total price including GST.

What is the formula for reverse GST calculation in Excel?

Using Excel to Reverse Calculate GST

Here's how to do it: Use the Formula: To reverse calculate GST, the formula is =Total Price / (1 + GST rate). For example, if the total price is ₹118 with an 18% GST, the person would type =118 / 1.18' in Excel to find the original price of ₹100.

How do you calculate GST backwards?

Adding 10% to the price is relatively easy (just multiply the amount by 1.1), reverse GST calculations are quite tricky:

  1. To figure out how much GST was included in the price you have to divide the price by 11 ($110/11=$10);
  2. To work out the price without GST you have to divide the amount by 1.1 ($110/1.1=$100)

How to work out 20% in reverse?

Calculating reverse percentages

  1. The original price of the top is unknown, but no matter what this price was, this is 100% of the value. The shop has then reduced prices by 20%. ...
  2. Multiply both sides by 100 to get 100%:
  3. £ 30 − 20 % = £ 30 − £ 6 = £ 24.

How to remove 18% GST from total amount?

Net price = Original cost – GST

For example, if the cost of a product after GST of 18% is Rs. 118, its original cost is 118 – [100/(100 + 18%)}], which equates to Rs. 100.