Flat Tax Rate Calculator

Worked example

Example: $60,000 gross income, $5,000 deductions, and a 22% flat rate estimates $12,100.00 tax and $47,900.00 net (20.17% effective rate).

When to use this

• You need a quick flat tax rate calculator estimate.
• You are comparing offers or scenarios side by side.
• You prefer browser tools that do not require an account.

Common examples

• $85,000 income with a 22% estimated effective rate → quick estimate of annual tax and take-home before detailed filings.
• Freelancer quarterly planning → compare two tax-rate assumptions for the same income to set aside cash.
• Side hustle add-on → estimate how a $6,000 extra income affects taxes at a higher bracket assumption.

Common mistakes

• Mixing annual and monthly rates or terms.
• Forgetting taxes, insurance, or fees that change the real total.
• Treating estimates as guaranteed quotes from lenders or employers.

How it works

Enter gross income and optional deductions, then choose Tax Year 2026 progressive federal brackets (Single, Married filing jointly, and other supported statuses) or a custom flat effective tax rate. An optional additional flat rate (for example state tax) can apply to taxable income. Results show total tax, net income, effective rate, and—when progressive—marginal bracket rate. For annual take-home by state with FICA, use Salary After Tax Calculator.

Limitations

This educational calculator applies either simple rates or custom progressive brackets to taxable income. It is not tax advice and does not account for every jurisdiction, tax year, filing-status rule, credit, or local rule. Consult a qualified tax professional for personal guidance.

Privacy and file handling

Your data stays on your device and is not uploaded.

Accuracy & methodology

This section documents how the calculator works, what it leaves out, and when results were last reviewed. Figures are educational estimates—not professional advice—and are not labeled "current" unless tied to automatically updated reference data.

Formula source or methodology

Progressive mode (default path): taxable income after deductions and Tax Year 2026 standard deduction; federal tax from IRS-aligned ordinary-income brackets in src/data/payroll/2026/federal.ts; optional additional flat rate on taxable income. Flat mode: user-supplied primary/additional rates × taxable income. Net = gross − total tax.

Jurisdiction

United States federal (educational); optional flat additional rate

Unit system

Currency; percent rates

Rounding method

Currency amounts round to two decimal places (half up via Math.round × 100 / 100). Effective rate uses Percentages round to two decimal places unless shown as whole percents in the UI.

Assumptions

• Progressive mode uses Tax Year 2026 federal brackets and standard deduction
• Flat mode is an explicit custom-rate what-if
• Annual income; monthly figures divide by 12
• Not a substitute for Salary After Tax (state + FICA take-home)

Known omissions

• Not tax, legal, investment, or lending advice. Confirm material decisions with qualified professionals.
• Federal income tax brackets, standard deduction, and credits for any tax year
• State and local income taxes
• Filing status (single, married, head of household, etc.)
• Payroll taxes (FICA, Medicare surtax) and self-employment tax
• Alternative Minimum Tax (AMT) and net investment income tax
• Capital gains preferential rates
• Credits and itemized deductions beyond a single deduction input
• Full state + FICA take-home (use Salary After Tax Calculator)

Test cases (automated)

• Progressive Single 2026 applies brackets after standard deduction
• $50,000 gross, $10,000 deductions, 20% flat rate → $8,000 tax and $42,000 net
• Deductions exceeding gross clamp taxable income to zero

Version & last verified

Logic version 2.0. Content and formulas last verified 2026-09-12.