- Supply amount
- –
- VAT (10%)
- –
- Total
- –
Calculate 10% VAT from the Supply Amount or the Total
Enter a supply amount to get the VAT and the total, or enter a total that already includes VAT to split it into the supply amount and the VAT. The rate is fixed at 10%, all math uses whole-won integers, and any fraction of a won is dropped. Handy for quotes, invoices, and quick price checks.
🧾 Great For
- Adding 10% VAT to a quoted price
- Finding the VAT portion inside a VAT-included total
- Splitting a receipt or invoice total into supply amount and VAT
- Comparing prices quoted with and without VAT
- Double-checking amounts before you write up a quote or invoice
📋 How to Use
- Pick a mode: Supply amount → VAT, or Total → Supply amount
- Type the amount in won — commas are fine, and a preview shows the comma-formatted value
- The supply amount, VAT, and total appear instantly
- Press "Copy result" to copy the three amounts as text
Frequently Asked Questions
How accurate is the calculation, and how are fractions of a won handled?
All calculations use exact integer arithmetic with no floating-point rounding, and any fraction of a won is dropped (rounded down). How fractions are handled on an actual tax invoice can differ depending on the issuing system or the parties involved, so if an issued amount differs from this result, check the basis used for that invoice.
What does this calculator assume?
It applies a fixed 10% VAT rate, the rate for general taxpayers. Other rates and other tax types are not calculated. This is a reference calculation, not tax advice — confirm anything that affects your filing with the tax authority or a tax professional.
What is the difference between the two modes?
Supply amount mode adds 10% to the amount you enter: VAT = supply amount ÷ 10 (rounded down) and total = supply amount + VAT. Total mode splits a VAT-included total: VAT = total ÷ 11 (rounded down) and supply amount = total − VAT, so supply amount + VAT always equals the total you typed. Because fractions are dropped, some totals cannot be reproduced by going back and forth. For example, a total of 120 won gives a supply amount of 110 won and VAT of 10 won, but entering 110 won in supply amount mode gives VAT of 11 won and a total of 121 won, not 120.
How do I enter amounts?
Type or paste whole won amounts. Commas are allowed (for example 1,000,000) and are ignored, and a preview line under the box shows the amount with commas. Decimals, negative numbers, and letters are not accepted, and the maximum is 1,000,000,000,000 won (1 trillion).