Start with the tax question you actually need to answer.
Use the complete federal calculator for a broad estimate or choose a focused tool to inspect one moving part. Every page shows its arithmetic, scope, tax year, primary sources, and exclusions before you act on the result.
6 calculators
Income and paychecks
Estimate a complete federal result, isolate marginal brackets, compare bonus tax, and reconcile payments.
Complete federal estimate
Complete estimateFederal income tax
Estimate federal income tax and employee payroll tax with a transparent breakdown.
Pay frequency planning
Complete estimateTake home pay
See the annual result plus monthly, semimonthly, biweekly, weekly, working day, and hourly annual averages.
Incremental federal tax
Focused calculationBonus tax
Compare federal income tax and employee payroll tax liability before and after a W-2 bonus, then reconcile a modeled flat supplemental withholding amount.
Ordinary income layers
Focused calculationTax brackets
Allocate ordinary taxable income across federal brackets and identify the rate on the next ordinary dollar.
Comparable federal rates
Focused calculationEffective tax rate
Compare federal income tax and the included federal burden with the same total entered income denominator.
Withholding reconciliation
Focused calculationTax refund
Reconcile a wage-only federal return estimate using separate Form W-2 box 1 and box 5 wages, named federal payment lines, and any Form 1040 line 36 allocation.
4 calculators
Payroll and self employment
Separate Social Security, Medicare, multiple employer withholding, and Schedule SE mechanics.
Employee and employer payroll
Focused calculationFICA tax
Calculate one employee's Social Security and regular Medicare from separate W-2 wage records, with employer matching and potential excess withholding.
Wage base and excess withholding
Focused calculationSocial Security tax
Calculate employee payroll tax at the per-person Social Security wage base and estimate potential excess withholding from two unrelated employers.
Liability versus withholding
Focused calculationAdditional Medicare Tax
Calculate 0.9% Additional Medicare Tax on Medicare wages from Form W-2 box 5, Form 4137 line 6, and Form 8919 line 6 plus self employment income from Schedule SE line 6, then compare modeled employer withholding.
Schedule SE payroll tax
Focused calculationSelf employment tax
Estimate Schedule SE Social Security and Medicare, Additional Medicare Tax on self employment income, and the deductible half.
3 calculators
Investing
Model long term gain and qualified dividend stacking, then test the separate 3.8% NIIT boundary.
Schedule D netting and rate stacking
Focused calculationCapital gains tax
Net short term and long term capital gains or losses, stack qualified dividends, and estimate the federal income tax effect.
Dividend rate stacking
Focused calculationQualified dividends tax
Stack qualified dividends above ordinary taxable income to show the supported federal preferential-rate allocation.
3.8 percent investment surtax
Focused calculationNIIT
Apply the 3.8 percent NIIT to the lesser of supported net investment income or excess modified AGI.
3 calculators
Retirement and deductions
Compare potential 401(k) and IRA savings or test standard versus itemized deductions.
Traditional contribution planning
Focused calculation401(k) tax savings
Compare federal income tax before and after a traditional 401(k) contribution while holding payroll wages constant.
Potential deductible contribution
Eligibility not modeledIRA tax savings
Estimate potential federal savings from a deductible traditional IRA contribution without deciding eligibility.
Bounded Schedule A comparison
Focused calculationStandard vs itemized
Compare the standard deduction with entered Schedule A categories and show the modeled federal tax difference.
3 calculators
Family and planning
Estimate supported dependent credits, compare joint and separate filing, and plan safe harbor payments.
Basic nonrefundable credits
Focused calculationChild Tax Credit
Estimate the basic Child Tax Credit and Credit for Other Dependents with phaseout and liability limits.
Two-spouse comparison
Eligibility not modeledJoint vs separate filing
Compare modeled joint and separate federal results without deciding filing eligibility or community-property treatment.
Annual payment target
Focused calculationEstimated tax safe harbor
Compare the 90 percent current-year target with the applicable 100 or 110 percent prior-year target.
4 calculators
Schedule 1-A deductions
Screen potential tips, overtime, vehicle interest, and senior deductions without deciding eligibility.
Schedule 1-A estimate
Eligibility not modeledTips deduction
Estimate the qualified tips deduction cap and MAGI phaseout without deciding whether tips or work qualify.
Schedule 1-A estimate
Eligibility not modeledOvertime deduction
Estimate the qualified FLSA overtime-premium deduction cap and MAGI phaseout without deciding eligibility.
Schedule 1-A estimate
Eligibility not modeledCar loan interest
Estimate the qualified vehicle-loan interest deduction cap and MAGI phaseout without deciding vehicle eligibility.
Schedule 1-A estimate
Eligibility not modeledSenior deduction
Estimate the enhanced senior deduction by eligible spouse and MAGI phaseout without determining eligibility.
State context
State liability remains a separate question.
The state explorer covers every state and DC, including local tax risk and special cases. It does not estimate a general state bill from a top rate. Only verified jurisdictions with no broad wage income tax can show zero wage tax.