VAT Calculator
Calculate VAT and the total in real time based on the supply value or the VAT-inclusive total. The rate is 10% by default and can be changed. All calculations happen in your browser.
Enter an amount to see the result.
How to use
- Choose whether to base it on the supply value or the total.
- Enter the amount and rate (10% by default).
- VAT, supply value, and total are shown in real time.
Calculation basis and verification sources
From a net amount, tax = net × rate and total = net + tax. From a tax-inclusive total, net = total ÷ (1 + rate). Each displayed amount is rounded to whole units. The 10% default is the general rate in Article 30 of Korea's Value-Added Tax Act.
Law checked: 2026-08-07. Ten percent is only a default for ordinary taxable Korean transactions; this tool does not determine zero-rating, exemption, simplified taxation, cross-border treatment, or another country's rate. Follow official tax guidance and invoice rules for filing and rounding.
Frequently asked questions
How is VAT calculated?
VAT is the supply value multiplied by the rate (10% by default). The total is the supply value plus VAT, which equals supply value × 1.1.
How do I get the supply value from the total?
Divide the VAT-inclusive total by 1.1 to get the supply value. VAT is the total minus the supply value.
Can I change the rate?
Yes. The default rate is 10%, and you can change the rate field to calculate with a different rate.
Practical example and verification criteria
VAT Calculator: Before calculating, check whether amounts are before or after tax, whether a term is in days, months, or years, whether a rate is annual or monthly, and whether start and end dates are inclusive. Align body measurements and currency, length, and time units as well. On-screen defaults may be illustrative assumptions, so replace them with your own conditions.
VAT Calculator: For a quick check, start with 110,000 ÷ 1.1 → 100,000 + 10,000 as a small input whose result relationship you can verify directly. Confirm that the input summary, units, and options match your intent before applying the tool to real values or a copy of the source; this reduces setup mistakes.
VAT Calculator: Read the input summary and formula, then check reversible relationships such as principal plus interest, net amount plus tax, or start date plus term. Test values around rounding, zero, one, and date boundaries. Compare health, finance, tax, and administrative results with current official information for the applicable region and effective date.
VAT Calculator · Work record: For real work, record the input conditions, selected options, and result together. Do not assume the same state will remain after a refresh or device change. Preserve important results separately using copy, download, a screenshot, or another method the page supports, then reopen them in the target environment.
VAT Calculator · Error check: If an error or unexpected result appears, reduce the input, run again with default options, and then change one condition at a time. Recording error messages and boundary values helps distinguish format issues, unsupported cases, and browser resource limits, and prevents an empty result from being mistaken for success.
VAT Calculator · Scope of use: Check the page guidance for browser processing versus server lookup, storage location, and supported scope. Use sensitive source material or secrets only when strictly necessary. High-impact work such as legal, financial, or medical decisions or changes to an operational system requires current authoritative information and a separate verification process.
This result is an estimate for reference only and may differ from actual figures depending on applicable rules and individual circumstances. Confirm important decisions with the relevant authorities or a professional.