VAT Calculator
Split a total into supply value and VAT or add VAT to a net price, with multi-line totals and Korea’s simplified-taxpayer VAT.
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VAT Calculator: complete guide
Walk through the steps and examples, or jump straight to the topic you need.
At a glance
- Calculation direction
- Two ways: split from the total, and add to the supply value.
- Tax rate
- You enter it yourself. The default of 10 is just a commonly used value.
- Rounding place
- Choose from 1 KRW, 10 KRW, 100 KRW units or no rounding.
- Sum guarantee
- The tax is rounded first, so supply value plus tax always equals the total.
- Multiple entries
- Up to 50 entries, each rounded and then added.
- Difference shown
- If the sum of entries differs from dividing everything at once, it tells you by how much.
- What it doesn't do
- It does not issue tax invoices or file on your behalf.
- Where it runs
- Calculated only in this browser; amounts are not sent to a server.
How to use VAT Calculator
Choose the calculation direction
If you want to know how much tax is in an amount you received, choose Split from total. If you're making a quote and want to know the amount to add tax to, choose Add to supply value. The input field names change to total and supply value depending on your choice.
Enter the amount and tax rate
Commas in the amount are read as they are. The rate is prefilled with 10 and you can change it. For tax-exempt or zero-rated transactions, enter 0. Invalid values are not calculated and the reason is shown in place.
Set the rounding place
If your client rounds to 10 KRW, change the tax rounding to 10 KRW units. Whichever place you choose, it calculates so that supply value plus tax equals the total, so it matches your tax invoice. When double-checking, choose no rounding to see the decimals.
Add multiple entries below
For several receipts, press Add entry and enter them one by one. The split amounts for each entry and the overall total are shown together. If the sum rounded per entry differs from dividing the whole at once, the difference is shown, so check which way you will file and use it.
What it’s good for
Rounding never leaves the sum off
Dividing 11,000 KRW by 10% gives a supply value of exactly 10,000 KRW, but amounts that don't divide evenly, like 33,333 KRW, are far more common. If you round the tax and the supply value separately, their sum ends up off from the original total by 1 KRW. This tool rounds the tax first and treats the remaining amount as the supply value. So for any amount, supply value plus tax equals the total exactly.
It doesn't decide the tax rate for you
The default of 10 is just the value most commonly used in Korea. Tax-exempt transactions, zero-rated transactions and simplified taxpayers are treated differently. This tool does not judge which rate is right; it only calculates with the rate you enter. The rate used is written in the result so it isn't confused with another transaction.
Worked examples
Split from total
11,000 KRW · rate 10%Supply value 10,000 KRW
VAT 1,000 KRWAn amount that doesn't divide evenly
33,333 KRW · rate 10% · 1 KRW unitsSupply value 30,303 KRW
VAT 3,030 KRWChoosing the rounding place
Swipe the table sideways to see the rest.
| Place | Tax example | When |
|---|---|---|
| 1 KRW units | 3,030 KRW | The most common on tax invoices |
| 10 KRW units | 3,030 KRW | When your client rounds to 10 KRW |
| 100 KRW units | 3,000 KRW | When setting a generous quote |
| No rounding | 3,030.27 KRW | When double-checking |
When the result isn’t what you expected
The sum is off by 1 KRW
It isn't off in this tool. If it differs from a value calculated elsewhere, that place may have rounded supply value and tax separately. Below the result it shows whether the sum matches, so check it.
The sum of entries differs from the whole
Rounding each entry piles up small remainders, so it differs from dividing everything at once. If a difference appears, the tool tells you by how much. If you issue tax invoices per entry, the per-entry sum is the right one.
I entered an amount but there is no result
The rate or amount contains something other than numbers. The reason is shown under the input field. Commas are fine to include.
I'm a simplified taxpayer. What do I enter?
Enter the rate that applies to you and calculate. This tool does not judge which taxation type you are. If you're unsure of the rate, check with your tax accountant first.
Key terms
- Supply value
- The price of goods or services before VAT is added.
- VAT
- The tax added by multiplying the supply value by the tax rate.
- Total
- The supply value plus VAT, the amount actually exchanged.
- Zero rate
- A transaction taxed at a 0% rate. It is different from tax-exempt.
VAT Calculator FAQ
I need to match to 10 KRW units. Is that possible?
You can change the tax rounding to 10 KRW or 100 KRW units. Whichever place you choose, it calculates so that supply value plus tax equals the total.
I have several receipts. Can I do them at once?
Add them one after another in the multiple entries area below. Each is rounded and then added; if the result differs from dividing the whole at once, the tool tells you how much it differs.
Can I file taxes with this calculation?
This tool only does the arithmetic of splitting amounts. It does not issue tax invoices or file on your behalf. For actual filing, follow your tax accountant or the Korean National Tax Service rules.
Does calculating in reverse give the same value?
If you take the total obtained by adding tax to a supply value and enter it again in Split from total, the original supply value comes back as it was.
Can I enter decimals in the amount?
Yes. Amounts with decimals, like foreign currency conversions, are calculated as they are.
Where are the results saved?
They are not saved. If you need them, press Copy result and keep them elsewhere.