Every result on MyClearCost is an estimate you can reproduce. This page is the short version of what the JavaScript actually does, and the list of things it will not pretend to know. If a number disagrees with your lender or payroll department, trust the document in your hand and tell us what you entered.
Paycheck / take-home
Annual gross salary is split by pay frequency (weekly, biweekly, semimonthly, or monthly). Traditional 401(k) percent and pre-tax health premiums reduce federal taxable wages. FICA generally still applies to 401(k) deferrals; cafeteria-plan health premiums often reduce both income tax and FICA — the tool follows that split.
Federal income tax uses 2026 ordinary-income brackets and standard deductions from IRS inflation adjustments (Rev. Proc. 2025-32): $16,100 single / married filing separately, $32,200 married filing jointly, $24,150 head of household. Tax is computed on annual taxable wages, then divided by the number of paychecks. That is not the same as IRS Publication 15-T percentage-method withholding, which also uses W-4 step entries, extra withholding, and Form W-4 year settings.
Social Security is 6.2% up to a $184,500 wage base (the 2026 figure used in the tool). Medicare is 1.45% with no cap, plus 0.9% Additional Medicare Tax above $200,000 single / head of household, $250,000 joint, $125,000 married filing separately. State income tax is a single percentage from a simplified table, which you can override. It is not your state’s full graduated return, and it ignores city tax, unemployment insurance, and disability withholdings.
Left out on purpose: tax credits, itemized deductions, bonuses, equity compensation, multi-job Form W-4, and most local taxes.
Mortgage (PITI + PMI + HOA)
Principal and interest use the standard fully amortizing payment: remaining balance, annual rate divided by 12, and term in months. Property tax starts from a statewide typical effective rate for the state you pick (see us-data.js) times home price, billed monthly; you can type a different annual tax. Homeowners insurance is an annual dollar amount you enter, divided by 12. PMI, when the down payment is under 20%, uses a simple annual-rate estimate on the loan amount — not your credit-score-based quote. HOA is a monthly add-on, not escrowed unless you treat it that way in real life.
Left out: discount points, origination fees in the payment, flood insurance, impound cushion months, and mid-year escrow analyses that change the draft amount.
Rent vs buy and refinance
Rent vs buy compares ending net worth after N years for two otherwise equivalent households.
Both start with the same liquid cash: down payment plus buyer closing costs (an editable illustrative percentage). The buyer spends that cash to purchase. The renter invests it. Each month, mortgage principal and interest, property tax, homeowners insurance, and maintenance (a flat percent of purchase price) set the buyer’s housing cash need; rent (grown monthly by the rent-growth assumption) sets the renter’s. Whoever has the lower housing cash need that month invests the difference at the same assumed annual return, compounded monthly as (1 + invest)^(1/12) − 1 on existing balances before that month’s contribution. Home value grows by the appreciation assumption once per year. At the horizon the model assumes a sale: selling costs (editable illustrative percentage) come out of equity, the mortgage balance is cleared, and buyer ending net worth is net sale proceeds plus any buyer investment balance. Renter ending net worth is the renter investment balance. The higher ending net worth wins.
Appreciation, rent growth, investment return, buyer closing costs, and selling costs are planning assumptions—not forecasts or national averages. State property-tax presets are planning estimates you can override. Mortgage-interest and property-tax deductions are left out. PMI is left out; if down payment is under 20%, the calculator warns that mortgage insurance may apply.
Refinance compares the current remaining amortization with a new loan plus closing costs, and reports monthly savings and a simple break-even in months.
Left out of rent vs buy: taxes on investment gains, portfolio fees, remodeling beyond the maintenance rate, HOA dues unless folded into maintenance, moving costs, and landlord risk if you later rent the property out.
Auto loan and car affordability
Amount financed is price minus down payment minus trade-in, plus sales tax using a statewide typical rate (override allowed). Some states tax the difference after trade-in; the tool uses a simple tax-on-taxable-amount model, not every county’s title-fee schedule. Payment is standard amortization. Affordability works backward from a target payment share of take-home-style income.
Left out: dealer add-ons, gap insurance, extended warranties, and negative equity rolled in unless you raise the price yourself.
Retirement, FIRE, and debt
401(k) / Roth growth compounds monthly contributions at a constant annual return, plus an employer match capped by the formula you enter. FIRE divides annual spending by a withdrawal rate to get a target, then solves years to that target given savings. Credit-card payoff amortizes a balance at a fixed APR with either a stated payment or an estimated minimum. Snowball vs avalanche applies extra dollars to the smallest balance or the highest APR while other debts stay at minimums.
Left out: sequence-of-returns risk, changing APRs, late fees, and required minimum distributions.
State rates
Sales-tax and property-tax starters are statewide typical figures for planning, not your county bill. Texas property tax is not New Jersey property tax. Oregon has no statewide sales tax. Override the field when you have a tax bill or a dealer worksheet.
Money Guides and Money Now
Money Guides are evergreen explainers next to the calculators. They define terms, show worked examples, and point back to the matching tool. Figures that depend on tax year or published rate tables are labeled; when a constant moves, we update the guide date.
Money Now pieces start from a current public development (for example a Fed decision or a weekly mortgage-rate print) and ask what could change for ordinary household money. They are educational explainers, not forecasts or advice. Sources and “as of” dates appear on each article; methodology for payment math still lives in the calculator sections above.
About describes who publishes the site. This page describes how numbers are built and checked.
Updates
Federal paycheck figures track tax year 2026 as implemented in the paycheck tool. When IRS or SSA publish new inflation adjustments or wage bases, those constants should move. Statewide tax shortcuts are reviewed more slowly; they are not a substitute for a current Department of Revenue table.
Related: disclaimer · guides · report an error.