What is gross-up and when do employers use it?
A gross-up is when an employer increases a payment so an employee receives a specific net (after-tax) amount. Instead of paying an employee a $1,000 bonus and watching them net only $650 after withholding, the employer calculates the gross amount needed — perhaps $1,575 in New York — so exactly $1,000 lands in the employee's pocket after all taxes are deducted. The employer effectively absorbs the tax burden on behalf of the employee.
Gross-ups are standard practice for signing bonuses where an offer letter promises a specific net amount, relocation packages covering moving expenses, employee achievement awards, and executive supplemental compensation. They're also useful during salary negotiations: knowing the gross required to produce a target take-home lets you anchor discussions to a specific number.
The gross-up formula
When all tax rates are known, the direct formula is: Gross = Desired Net ÷ (1 − Total Tax Rate). For a bonus in a no-income-tax state, the components are 22% federal supplemental + 6.2% Social Security + 1.45% Medicare = 29.65% total, giving a gross-up factor of 1.421×. Add New York's 6.85% state rate and the factor rises to 1.575×; in California's top bracket (13.3%) the factor reaches 1.724×. This calculator displays the exact factor for your state and filing status after every calculation, so you can multiply any future net amount instantly.
Run the resulting gross through the bonus tax calculator to verify all withholding line items before processing payroll, or use the payroll tax calculator to see the full federal + FICA + state breakdown for any gross amount.
Flat-rate vs. aggregate gross-up
There are two IRS-recognized methods. The flat-rate (supplemental) method applies a fixed 22% federal withholding to bonuses — it makes the math clean and predictable, and is what this calculator uses for the Bonus mode. The aggregate method combines the bonus with the employee's regular wages and applies their actual bracket, which generally produces a higher withholding for high earners but a lower withholding for lower earners. For regular salary gross-up, this calculator uses the employee's progressive 2026 brackets via an iterative solver that converges within $0.01.
Employee use: engineering a salary target
Job seekers use the reverse problem constantly. If your monthly budget requires $5,500 take-home — rent, loan payments, savings, and living expenses — what annual gross salary must you negotiate for? Because federal income tax uses progressive brackets, higher gross income pushes you into higher marginal rates, which changes the effective rate you need to account for. Switch to Salary Negotiation mode, enter your target monthly net, select your state, and the calculator solves backward iteratively. Confirm the resulting gross against any offer using the take-home pay calculator. For a full paycheck view that includes 401(k) contributions and health insurance deductions, run the gross through the free payroll calculator.