Colorado Bonus Calculator
Bonus Details
Federal W-4 Settings
Colorado Withholding (Form DR 0004)
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.
- Colorado has a flat income tax rate of 4.4 percent and does not use a separate supplemental withholding rate. If your bonus is paid separately, employers typically withhold the flat 4.4 percent.
- Colorado employees also contribute to the Family and Medical Leave Insurance (FAMLI) program at 0.45 percent of wages, up to the Social Security wage base.
- If your bonus is combined with a regular paycheck (aggregate method), withholding is computed on the combined amount using your W-4 and DR 0004. 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 Colorado Bonus Calculator?
The Colorado Bonus Calculator is a payroll withholding estimator based on the 2025 federal and Colorado rules coded into the tool. You enter a gross bonus or desired take-home amount, your annual salary, pay frequency, filing information, W-4 settings, Colorado withholding details, deductions, and optional year-to-date payroll data.
A Colorado bonus calculator estimates the amount left from your bonus after the withholding rules selected in the tool are applied. It calculates federal and Colorado income tax withholding, Social Security, Medicare, Additional Medicare tax, and Colorado FAMLI, then subtracts those amounts from the gross bonus to estimate your bonus take-home pay.
The calculator also shows the withholding under the alternative federal and Colorado bonus methods. Beyond the bonus itself, it estimates the taxes and net pay for the entire pay period. An annual snapshot shows estimated federal income tax, Colorado income tax, FAMLI premiums, projected income tax withholding, and a projected refund or amount due based on the information entered.
How the Colorado Bonus Calculator Formula Works
The core calculation subtracts all withholding assigned to the bonus from the gross bonus. The exact federal and Colorado income tax amounts depend on the withholding methods selected.
- B is the gross bonus.
- F is federal income tax withheld from the bonus.
- SS is Social Security tax assigned to the bonus.
- M is regular Medicare tax on the bonus.
- AM is Additional Medicare tax assigned to the bonus.
- CO is Colorado income tax withheld from the bonus.
- FAMLI is the Colorado FAMLI premium assigned to the bonus.
Under the federal flat method, the code withholds 22% while cumulative supplemental wages remain within the $1,000,000 threshold. Any part above that threshold is withheld at 37%. Under the aggregate method, the calculator adds the bonus to regular taxable wages, calculates federal withholding on the combined check, and subtracts federal withholding on regular wages alone.
Colorado works similarly. The flat method applies 4.4% directly to the bonus. The aggregate method calculates Colorado withholding on combined taxable wages and subtracts the regular-only amount.
Worked Example
Suppose you enter a $5,000 gross bonus, a $75,000 annual salary, biweekly pay, Married Filing Jointly status, and the flat federal and Colorado methods. Assume no deductions, W-4 adjustments, extra withholding, or prior year-to-date wages.
- Federal bonus withholding: $5,000 × 22% = $1,100.
- Social Security: $5,000 × 6.2% = $310.
- Medicare: $5,000 × 1.45% = $72.50.
- Additional Medicare: $0 because the threshold is not reached in this example.
- Colorado income tax withholding: $5,000 × 4.4% = $220.
- FAMLI: $5,000 × 0.45% = $22.50.
Total bonus withholding is $1,725. The calculator therefore produces an estimated bonus take-home amount of $3,275 and an effective withholding rate of 34.50%.
Social Security and FAMLI can be limited by the $176,100 wage base in the code. Additional Medicare withholding starts after year-to-date Medicare wages plus current wages exceed $200,000. These thresholds can change the result for higher earners.
How to Use the Colorado Bonus Calculator: Step by Step
- Choose Estimate take-home from a bonus amount to start with a gross bonus, or select Gross-up to solve for the gross bonus required to reach a desired net amount.
- Enter the bonus amount. In estimate mode, enter the gross bonus. In gross-up mode, enter your desired after-withholding bonus.
- Select the federal bonus withholding method and Colorado bonus withholding method. The calculator offers flat and aggregate methods for each.
- Enter your base annual salary, then select weekly, biweekly, semimonthly, or monthly pay frequency.
- Select your federal filing status. Then enter any applicable W-4 Step 2, Step 3, Step 4(a), Step 4(b), and Step 4(c) information.
- Select your Colorado filing status and enter any extra Colorado withholding per paycheck.
- Enter pre-tax and post-tax deductions for one regular paycheck. The code uses pre-tax deductions to reduce federal and Colorado income-tax wages, but not Social Security or Medicare wages.
- If available, enter prior year-to-date Social Security wages, Medicare wages, supplemental wages, pay periods received, and federal and Colorado income tax already withheld.
- Check the acknowledgment confirming that the result is a withholding estimate, then calculate.
The main result is your estimated bonus take-home amount. The calculator also displays the effective withholding rate and each withholding component. You can review the full pay-period estimate and the annual snapshot to see how the bonus affects the broader payroll calculation. In gross-up mode, the tool also displays the required gross bonus.
What Affects Your Colorado Bonus Take-Home?
Your result depends on more than the bonus amount. The selected withholding methods, regular salary, filing status, W-4 entries, payroll deductions, year-to-date wages, and prior withholding can all affect calculations shown by the tool.
| Tax or Premium | Rule Used by the Calculator |
|---|---|
| Federal supplemental withholding | 22% under the flat method up to the remaining $1,000,000 supplemental-wage threshold; 37% above it |
| Social Security | 6.2% up to the 2025 wage base of $176,100 |
| Medicare | 1.45% of Medicare wages |
| Additional Medicare | 0.9% after Medicare wages exceed $200,000 |
| Colorado income tax | 4.4% under the flat bonus method |
| Colorado FAMLI | 0.45% of wages up to the $176,100 wage base |
Flat Versus Aggregate Withholding
The flat method calculates bonus income tax withholding directly from the bonus. The aggregate method treats the bonus as part of the current paycheck for withholding purposes. Because the combined check is annualized inside the calculator, the aggregate result can differ significantly from the flat-method result. The tool shows the alternative method for comparison.
Why Year-to-Date Information Matters
Prior wages help determine whether Social Security and FAMLI wage limits have already been partly or fully reached. Prior Medicare wages affect Additional Medicare withholding. Prior supplemental wages determine whether a bonus crosses the $1,000,000 federal supplemental-wage threshold. Existing federal and Colorado withholding also affects the calculator's projected refund or amount due.
Important Limitations
This calculator estimates withholding using the 2025 rules and formulas written into its code. Withholding is not the same as your final tax liability. Actual payroll results may differ because of employer payroll procedures, other income, deductions, credits, benefit treatment, tax-law changes, and information not entered here. The results are not tax, payroll, financial, or legal advice.
Frequently Asked Questions
How much tax is withheld from a bonus in Colorado?
The amount depends on the withholding methods and your payroll information. In the calculator's flat-method setting, federal supplemental withholding is generally 22% below the applicable $1,000,000 threshold, while Colorado withholding is 4.4%. Social Security, Medicare, Additional Medicare when applicable, and Colorado FAMLI may also reduce the bonus.
Are bonuses taxed at 22% in Colorado?
No. In this calculator, 22% is a federal supplemental withholding rate used by the flat federal method. It is not a special final tax rate on the bonus. The calculator treats the bonus as ordinary annual income when estimating federal tax liability in its annual snapshot.
What is the difference between flat and aggregate bonus withholding?
The flat method applies a specified withholding rate directly to the bonus. The aggregate method combines the bonus with regular taxable wages, calculates withholding on the combined paycheck, and subtracts the withholding calculated on regular wages alone. The Colorado Bonus Calculator can calculate both methods and displays the alternative result for comparison.
Does this Colorado bonus calculator include Social Security and Medicare?
Yes. The calculator includes 6.2% Social Security withholding up to the $176,100 wage base, 1.45% Medicare withholding, and 0.9% Additional Medicare withholding after the coded $200,000 wage threshold is crossed. Optional year-to-date wage entries help the tool determine how much of those thresholds remains.
Does the calculator include Colorado FAMLI withholding?
Yes. The code applies a 0.45% Colorado FAMLI employee premium to applicable wages, limited by the same $176,100 wage base used in the calculator for 2025 Social Security wages. Prior year-to-date Social Security wages are used to determine how much wage base remains for the current paycheck and bonus.
How do I calculate the gross bonus needed for a specific take-home amount?
Select the calculator's gross-up mode and enter the net bonus you want to receive. The code repeatedly tests different gross bonus amounts until it finds a gross amount that produces at least the requested take-home value. The final required gross bonus is rounded upward to the next cent.
How accurate is the Colorado Bonus Calculator?
The calculator follows the 2025 federal and Colorado formulas coded into the tool, so its result depends on how closely your entries match your payroll situation. Optional year-to-date data can improve the estimate. Actual withholding and final tax liability can still differ because of payroll practices, other income, credits, deductions, and later tax changes.