Korea VAT 10% Calculator: Tax

A simple and practical VAT management app designed for Korean sole proprietors and corporations.
Handle VAT calculations and biannual tax payment preparation without the hassle.

Core Features
- Two-Way Instant Calculation: Enter the supply price to get the VAT-inclusive amount, or reverse-calculate the supply price from a VAT-inclusive total.
- Sales & Purchase Calendar: Record daily sales and purchase transactions with counterparty auto-complete.
- VAT Payment Manager: Enter sales/purchase amounts for Period 1 (Jan–Jun) or Period 2 (Jul–Dec). Auto-calculates the tax payable or refundable after deducting any preliminary tax paid.
- Calendar Auto-Sync: Automatically pulls calendar transaction data into the payment screen.
- Data Backup: Backup and restore all app data via JSON file.

Recommended For
- Sole proprietors and corporations preparing their own VAT filings.
- Anyone who needs to quickly convert between supply price and VAT-inclusive amounts.
- Business owners who want to track monthly sales and purchases on a visual calendar.
- Those who want to estimate their biannual VAT liability in advance.

Accurate Tax Calculation
- Output Tax (Sales × 10%) − Input Tax (Purchases × 10%) = Tax Payable / Refundable, calculated automatically.