VAT calculator

Add VAT to a net amount or back it out from a total.

VAT rate (%)

1. Supply value → VAT · total

Supply value KRW = -

2. Total (incl. VAT) → supply value

Total KRW = -

A supplier quotes 2,000,000 and then asks whether that is before or after VAT, and the two answers are 200,000 apart. Or an invoice arrives showing only one figure and your bookkeeping needs it split into net and tax. This calculator handles both directions: forwards from a supply value, and backwards from a total that already has VAT baked in.

How it works

Adding VAT to a supply value

Enter the net amount in the first box. The tax and the total are:

VAT = supply value × rate ÷ 100 total = supply value + VAT

At the default 10%, a supply value of 1,000,000 carries 100,000 of VAT and invoices at 1,100,000.

Working backwards from a VAT-inclusive total

Enter the gross figure in the second box:

supply value = total ÷ (1 + rate ÷ 100) VAT = total − supply value

This is the step people most often get wrong. Subtracting 10% from a VAT-inclusive total does not give the net amount — 1,100,000 minus 10% is 990,000, but the correct answer is 1,100,000 ÷ 1.1 = 1,000,000. The percentage was added to the smaller number, so it has to be divided back out of the larger one, not subtracted from it.

Changing the rate

The rate box defaults to 10, the standard VAT rate in Korea, which has applied since the tax was introduced in 1977 and remains 10% at the time of writing. Korea has no reduced rate, though some supplies are zero-rated or exempt. Type a different figure to run the same arithmetic for another jurisdiction; both calculators pick the new rate up immediately.

Rounding

Amounts are rounded to whole currency units, so a figure here can sit a unit away from an invoice depending on how the issuing system rounds. For how VAT should be reported, invoiced, or reclaimed in your own situation, check the official tax authority guidance or a qualified accountant.

Terms explained

Supply value: The net price of goods or services before VAT is added. Also called the taxable amount or net amount.
VAT: Value added tax — a consumption tax charged as a percentage of the supply value at each stage of sale.
VAT-inclusive total: The gross figure a customer actually pays: supply value plus VAT.
Zero-rated: Supplies taxed at 0%. VAT is still technically charged, so related input tax can normally be reclaimed.
Exempt: Supplies outside the VAT charge altogether, such as certain medical, educational, and financial services. Input tax on these generally cannot be reclaimed.

Frequently asked questions

How do I remove VAT from a total?

Divide the total by 1 plus the rate as a decimal. At 10% that means dividing by 1.1, so 550,000 becomes a 500,000 supply value and 50,000 of VAT. Subtracting 10% from the total instead is the common error and gives a figure that is too low.

What is the VAT rate in Korea?

The standard rate is 10% and has been since 1977. Korea does not operate reduced rates, but certain supplies — exports among them — are zero-rated, and things like basic unprocessed foodstuffs, medical care, and education are exempt. This reflects the position at the time of writing; confirm current rules with the National Tax Service.

Why can't I just take 10% off the gross amount?

Because the 10% was calculated on the net figure, not the gross one. Ten percent of 1,000,000 is 100,000, but ten percent of the 1,100,000 total is 110,000 — a different base, so subtracting overshoots. Division reverses the step correctly.

Can I use this for VAT in another country?

Yes. Replace the value in the rate field with whatever rate applies where you are trading and both calculations follow it. The arithmetic is the same everywhere; only the rate and the rules on exemptions change.

The result differs from my invoice by one unit

That is rounding. This tool rounds to the nearest whole currency unit, while accounting systems may round at the line level or truncate instead. On a single figure the gap is a unit or two; on a long invoice it can accumulate slightly.