Why is so much tax withheld from my bonus?

Bonuses are supplemental wages. The IRS requires employers to withhold at least 22% federally using the flat rate method. Under the aggregate method, withholding can be even higher because the combined check pushes into a higher bracket. However, withholding is not your final tax — you reconcile when you file.

What is the flat 22% bonus tax method?

Your employer withholds exactly 22% of your bonus for federal income tax — regardless of your marginal bracket. This applies to bonuses up to $1 million per year. If your marginal rate is below 22%, you receive the excess back as a refund at filing.

What is the aggregate bonus tax method?

Your employer adds the bonus to your most recent paycheck and calculates withholding based on the combined amount annualized. This can push you into a higher withholding bracket — resulting in more withheld upfront — but does not change your actual annual tax liability.

Are bonuses taxed at a higher rate than regular salary?

No. Bonuses are taxed at the same marginal rates as regular income. The confusion comes from withholding: the flat 22% can be more or less than your actual rate. At filing, all income is combined. A bonus does not create a special tax bracket.

Can I reduce taxes withheld from my bonus?

Yes. The most effective strategy is maximizing 401(k) contributions before or during the pay period the bonus is processed. You can also request a W-4 adjustment, though many payroll systems cannot accommodate this for one-time supplemental payments. Talk to HR before the bonus is processed.

How to Use the Bonus Tax Calculator: Complete Guide

When your employer announces a $10,000 bonus, the number that matters is how much lands in your bank account — and that depends on which IRS-approved withholding method your employer uses. The flat 22% method and the aggregate method can produce very different net checks. This guide walks through every calculator input and explains exactly what each result means.

The Two IRS Methods for Taxing Bonuses

Bonuses are classified as supplemental wages by the IRS. Unlike regular salary, they have two distinct withholding methods. Your employer chooses — and knowing the difference helps you anticipate your take-home and plan accordingly.

IRS supplemental wage withholding methods compared

Method	How It Works	Typical Rate	Best For
Flat Rate (22%)	IRS mandates a flat 22% federal withholding on bonuses under $1 million	22% federal + FICA + state	Most employees — simple and predictable
Aggregate Method	Bonus added to last paycheck; withholding based on combined annualized amount	Varies — often higher for higher earners	Some payroll systems default to this
37% Rate	Applies to supplemental wages above $1 million per year from one employer	37% on amount over $1M	High earners with very large bonuses

What Each Calculator Input Does

The bonus tax calculator needs key information to compute your net check accurately. Enter each field carefully — small differences in annual salary can shift your effective withholding rate under the aggregate method.

Bonus amount: The gross bonus before any taxes or deductions
Annual salary: Your base salary — used for aggregate method and state tax brackets
Filing status: Single, married filing jointly, or head of household
State: State income tax rates range from 0% (Texas) to 13.3% top bracket (California)
Pay frequency: How often you receive regular paychecks — affects the aggregate calculation
Withholding method: Flat 22% or aggregate — ask HR if you are unsure which your employer uses

💡Ask HR Which Method They Use

Most employers use the flat 22% method for simplicity. But some payroll systems default to the aggregate method, which can result in 30-35%+ federal withholding if the combined check lands you in a higher bracket. Knowing in advance lets you plan or request an adjustment.

Reading Your Results

Bonus tax calculator output breakdown

Output Line	What It Represents	Notes
Federal Income Tax	Amount withheld using your selected method	22% flat or based on marginal rate (aggregate)
Social Security Tax	6.2% on wages up to the wage base ($176,100 in 2025)	Applies fully if under the annual cap
Medicare Tax	1.45% standard + 0.9% additional Medicare if total wages exceed $200K	No income cap on the base 1.45%
State Income Tax	Varies by state — some use separate supplemental rates	0% in no-income-tax states
Net Bonus	The amount deposited in your account after all withholding	Your actual take-home

After You Run the Calculator

If withholding looks higher than expected, remember: over-withheld amounts come back as a refund when you file your annual return. If you want to reduce the impact, maximize retirement contributions before your bonus pays out — 401(k) contributions reduce taxable income and lower your effective withholding under most payroll systems.

ℹ️Withholding Is Not Final Tax

Many employees see a large amount withheld and assume they paid too much tax. Withholding is a prepayment — not the final bill. If your marginal rate is lower than the 22% withheld, you receive a refund at filing. The calculator shows withholding, not permanent tax cost.

Calculate Your Bonus Take-Home Now

Enter your bonus, salary, state, and filing status to see exactly what you net after federal, state, and FICA taxes.

Open Bonus Tax Calculator →