There is a one-won gap.

When working backward, the dropped fraction is placed in VAT. That is why 910 won is 1 won more than 909 won.

Only whole won are accepted. A decimal shows a note and clears the result.

What about exempt sales?

Exempt sales and simplified-tax payments are not counted. This screen only handles 10%.

It is not saved. The arithmetic stays in this tab.

Home VAT calculator

Won below one are dropped, and the total is also written in Korean. The amount stays in this browser.

Net price (VAT excluded)

Direction: Add VAT puts 10% on the net price. Remove VAT takes the net price back out of a total.
Ten percent: VAT is the net price divided by 10, with anything under one won dropped. The total is the net price plus that VAT.
Fraction: Working backward, the net price is 10/11 of the total with the fraction dropped, and VAT is the total minus that net price. The dropped fraction can make VAT one won higher.
Korean line: The Korean line starts with 일금 and writes 일 before 십, 백, and 천 so it can be copied onto a quote.
Limit: Amounts over 100 billion won, decimals, zero or less, and text that is not a number are refused. Commas and the won sign are ignored.
Where: The arithmetic finishes in this browser. Nothing is uploaded.

VAT on 12,345 won is 1,234 won and the total is 13,579 won. Removing VAT from 10,000 won gives a net price of 9,090 won and VAT of 910 won.

A price marked excluded and a price marked included are not the same number. Changing direction moves both the net price and the total.

An invoice is written in whole won. The screen keeps the dropped fraction visible.

Adding VAT to 1,000,000 won gives 100,000 won of VAT, a total of 1,100,000 won, and 일금 일백일십만원정.

Removing VAT from 10,000 won says that VAT is 1 won above 10% of the net price.

Entered1,000,000 won

QThere is a one-won gap.: AWhen working backward, the dropped fraction is placed in VAT. That is why 910 won is 1 won more than 909 won.
QWhat about decimals?: AOnly whole won are accepted. A decimal shows a note and clears the result.
QWhat about exempt sales?: AExempt sales and simplified-tax payments are not counted. This screen only handles 10%.
QIs it saved?: AIt is not saved. The arithmetic stays in this tab.