Arizona Bonus Calculator
Bonus Details
Federal W-4 Settings
Arizona Withholding (Form A-4)
Deductions (Per Regular Paycheck)
Year-To-Date Data (Optional, Improves Accuracy)
Your Bonus Estimate
- Bonuses are not taxed at a special bonus rate when you file. They are ordinary income taxed at your regular marginal rate.
- The 22 percent federal flat rate is simply a withholding method employers use on supplemental wages paid separately.
- Arizona has a flat income tax rate of 2.5 percent and does not use a separate supplemental withholding rate. Your elected Form A-4 percentage is applied to your taxable wages.
- If your bonus is combined with a regular paycheck (aggregate method), withholding is computed on the combined amount using your W-4 and Form A-4. This can push that single check into a higher bracket, which is why bonuses often look over-taxed in the pay period.
- When you file your return, your total annual income determines your true liability. Over-withholding on the bonus becomes part of your refund. Under-withholding becomes tax due.
- Gross-up mode solves for the gross bonus your employer must pay so your take-home equals the target you enter.
What Is the Arizona Bonus Calculator?
The Arizona Bonus Calculator is a payroll withholding estimator for bonuses paid to Arizona employees. It combines the bonus amount with your salary, pay frequency, federal filing status, W-4 settings, Arizona Form A-4 percentage, paycheck deductions, and optional year-to-date payroll information.
The calculator estimates your net bonus by subtracting federal bonus withholding, Social Security, Medicare, Additional Medicare Tax, and Arizona withholding from the gross bonus. It also shows the full paycheck impact, an annual tax snapshot, and a comparison between the federal flat and aggregate bonus withholding methods.
You can use the calculator in two ways. Estimate mode starts with a gross bonus and calculates take-home pay. Gross-up mode starts with the net bonus you want to receive and solves for the gross bonus required to reach that target after the calculator's estimated withholding.
How the 2025 Arizona Bonus Withholding Formula Works
The calculator starts with the gross bonus and subtracts each withholding component that applies to that bonus.
- B is the gross bonus.
- F is federal income tax withheld from the bonus.
- SS is Social Security withholding allocated to the bonus.
- M is Medicare withholding on the bonus.
- AM is Additional Medicare Tax withholding allocated to the bonus.
- AZ is Arizona income tax withheld from the bonus.
Under the federal flat method, supplemental wages are withheld at 22% until cumulative supplemental wages reach $1,000,000. Any part above that threshold is withheld at 37%.
Here, Y is prior year-to-date federal supplemental wages. Under the aggregate method, the calculator adds the bonus to regular taxable wages, calculates federal withholding on the combined check, then subtracts withholding on regular wages alone.
Social Security is 6.2% up to the calculator's 2025 wage base of $176,100. Medicare is 1.45% of the bonus. Additional Medicare withholding is 0.9% on wages above the $200,000 employer withholding threshold, using prior year-to-date Medicare wages plus the current pay period.
For example, enter a $5,000 gross bonus, $75,000 salary, biweekly pay, married filing jointly, the flat federal method, a 2.5% Arizona withholding election, and zero for all deductions and year-to-date fields. Federal bonus withholding is $1,100, Social Security is $310, Medicare is $72.50, Additional Medicare is $0, and Arizona withholding is $125. Total bonus withholding is $1,607.50.
The estimated bonus take-home is therefore $3,392.50, with an effective withholding rate of 32.15%.
How to Use the Arizona Bonus Calculator: Step by Step
- Choose Estimate take-home from a bonus amount or Gross-up: solve for a target take-home amount.
- Enter the gross bonus amount, or enter your desired net bonus if you selected gross-up mode.
- Select the federal bonus withholding method: flat 22% or aggregate.
- Enter your base annual salary, then select weekly, biweekly, semimonthly, or monthly pay frequency.
- Select Single, Married Filing Jointly, or Head of Household as your federal filing status.
- Enter any applicable W-4 Step 3 dependent credits, Step 4(a) other income, Step 4(b) deductions, Step 4(c) extra withholding, and select Step 2 if applicable.
- Select your Arizona Form A-4 withholding percentage and enter any extra Arizona withholding per check.
- Enter your pre-tax and post-tax deductions per regular paycheck. These fields affect the regular paycheck calculations according to the calculator's coded rules.
- Add optional year-to-date Social Security wages, Medicare wages, supplemental wages, pay periods received, and federal and Arizona withholding for a more informed projection.
- Check the acknowledgment that the results are withholding estimates, then run the calculation.
The main result is your estimated bonus take-home. The calculator also shows the effective withholding percentage, each tax component, the full pay-period estimate, and an annual income-tax snapshot. In gross-up mode, it additionally shows the required gross bonus, rounded upward to the next cent by the calculator's solving method.
What Your Arizona Bonus Calculator Results Mean
Bonus Withholding Breakdown
The first result section separates federal income tax, Social Security, Medicare, Additional Medicare Tax, and Arizona withholding. It also displays the federal withholding amount that would result from the other federal method. This comparison can help explain why the amount withheld from a bonus may change depending on payroll treatment.
| Item | Rule Used by the Calculator |
|---|---|
| Federal flat supplemental withholding | 22%, with 37% on supplemental wages above the $1,000,000 threshold |
| Social Security | 6.2% up to the 2025 $176,100 wage base |
| Medicare | 1.45% |
| Additional Medicare | 0.9% above $200,000 of applicable wages |
| Arizona withholding election | 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or 3.5% |
| Arizona annual tax estimate | 2.5% of calculated Arizona taxable income |
Regular Pay and Deductions Matter
The calculator derives regular gross pay by dividing annual salary by the selected number of pay periods. Entered pre-tax deductions reduce federal and Arizona income-tax wages on the regular paycheck, but the code does not reduce Social Security or Medicare wages with those deductions. Post-tax deductions reduce estimated take-home pay without reducing calculated taxes.
Pre-tax and post-tax deductions are each capped at the regular gross pay for the period. The calculator does not subtract the entered regular-paycheck deduction amounts directly from the bonus itself.
Year-to-Date Information Can Change the Estimate
Year-to-date Social Security wages determine how much room remains under the $176,100 wage base. Medicare wages determine whether the $200,000 Additional Medicare threshold is crossed. Supplemental wages determine whether the federal $1,000,000 threshold is reached. Prior withholding and pay periods received are also used for the projected refund or amount due calculation.
This calculator is based specifically on the 2025 federal and Arizona rules stored in its code. Results are estimates, not a tax return or professional payroll calculation. Actual withholding and final tax liability can differ because of payroll practices, other income, credits, deductions, later earnings, updated tax rules, and information not entered into the calculator.
Frequently Asked Questions
How much tax is withheld from a bonus in Arizona?
The amount depends on several withholding components, not one Arizona bonus tax rate. This calculator includes federal income tax withholding, Social Security, Medicare, possible Additional Medicare Tax, and Arizona withholding. The final percentage changes with your bonus amount, federal method, Form A-4 election, year-to-date wages, and other entered payroll information.
Is an Arizona bonus taxed at 2.5%?
Not by itself. The calculator uses 2.5% as Arizona's coded flat income tax rate for its annual Arizona tax estimate, but bonus withholding uses the Form A-4 percentage you select. Federal income tax, Social Security, Medicare, and possible Additional Medicare withholding can also be taken from the bonus.
Why is 22% withheld from my bonus?
The calculator uses 22% as the federal supplemental withholding rate when the flat method is selected and applicable supplemental wages remain below $1,000,000. That 22% is only federal income tax withholding. Social Security, Medicare, possible Additional Medicare Tax, and Arizona withholding are calculated separately, so total withholding can be higher.
What is the difference between the flat and aggregate bonus methods?
The flat method generally applies the coded 22% federal supplemental rate, subject to the $1,000,000 supplemental wage threshold. The aggregate method adds the bonus to regular taxable wages, calculates withholding on the combined paycheck, and subtracts the regular-pay withholding. The calculator shows the alternative method for comparison.
Do pre-tax deductions reduce the tax on my bonus?
Not directly in this calculator. The pre-tax deduction field is defined as an amount per regular paycheck. It reduces regular federal and Arizona income-tax wages in the calculator, but it does not reduce the bonus amount or Social Security and Medicare wages. The exact treatment of deductions on an actual bonus depends on payroll arrangements.
Can I calculate the gross bonus needed for a specific take-home amount?
Yes. Select gross-up mode and enter the net bonus you want to receive. The calculator repeatedly tests gross bonus amounts until it finds an amount whose estimated take-home reaches the target. It then rounds the required gross bonus upward to the next cent and displays the withholding breakdown for that solved amount.
How accurate is the Arizona Bonus Calculator?
It is an estimate based on the 2025 tax rates, thresholds, standard deductions, and withholding logic coded into the tool. Accuracy depends heavily on the information entered, especially year-to-date wages and withholding. Actual payroll calculations and your final tax return may differ, so the result should not be treated as tax or payroll advice.