🧾 Gross-up Calculator

"Gross-up" means starting from a fixed net (take-home) amount and working backward to find the gross (pre-tax) amount that, after tax, leaves exactly that net amount. Normal payroll math goes the other direction — gross minus tax equals net — but for freelance invoices, contractor fees, expat assignments, or settlement payments, you often want to guarantee the other party receives a specific net figure. The formula is Gross = Net ÷ (1 − Tax rate). For example, to guarantee a net of $8,000 at a 20% flat tax rate: Gross = 8,000 ÷ (1 − 0.20) = 8,000 ÷ 0.8 = $10,000, and tax withheld is $2,000. A common mistake is simply adding the tax rate to the net amount (8,000 × 1.20 = $9,600), which under-shoots the target net once tax is actually applied — you must divide, not multiply.

This calculator intentionally assumes a single flat tax rate to keep the math transparent. In practice, employment income tax in most countries (including Korea) uses a progressive bracket structure where the marginal rate rises with income, plus separate deductions (social insurance, pension, health insurance, etc). To gross-up an actual salary precisely, you would need to account for each bracket, standard deductions, and dependents — a simple division cannot capture that. This tool is accurate for flat-withholding cases like freelance invoices (e.g. a flat 3.3% withholding), but for salaried payroll with bracket-based tax, treat the result here as a rough estimate only and verify with a full progressive salary calculator. The larger the target net amount and the more bracket boundaries it crosses, the bigger the gap between this flat-rate estimate and the true progressive-tax result.