How we calculate

Paycheck calculators

1. Gross pay

Salary mode divides annual salary by the number of pay periods (52 weekly, 26 bi-weekly, 24 semi-monthly, 12 monthly). Hourly mode multiplies rate × regular hours, adds overtime hours at 1.5× the rate, and annualises at 52 weeks.

2. Pre-tax deductions

Traditional retirement contributions reduce federal income-tax withholding wages but generally remain subject to Social Security and Medicare. State treatment can differ: Pennsylvania taxes employee retirement contributions; New Jersey excludes qualifying 401(k) deferrals but taxes employee 403(b) and 457 contributions. The New Jersey calculator lets you choose the plan.

The combined Section 125 field models voluntary employee salary reductions for federally qualifying benefits. These reduce federal and FICA wages. New Jersey keeps them in state wages; California separates HSA contributions because their state treatment differs from qualifying health/FSA deductions. Other benefit-specific exclusions and employer-funded plans need separate review.

3. Federal income tax withholding

We implement Worksheet 1A of IRS Publication 15-T (2026), the percentage method for automated payroll systems, for a Form W-4 from 2020 or later:

adjusted annual wage = annual taxable wages + W-4 4(a) other income
                      − W-4 4(b) deductions − (Step 2 box checked ? 0 : $8,600, or $12,900 if married filing jointly)
tentative withholding = STANDARD or STEP-2-CHECKBOX schedule applied to the adjusted annual wage
annual withholding    = max(0, tentative − W-4 Step 3 credits)
per-paycheck          = annual withholding ÷ pay periods + W-4 4(c) extra withholding

The published schedules equal the ordinary 2026 brackets shifted by the standard deduction ($16,100 single, $32,200 joint, $24,150 head of household) less the built-in amount above; the checkbox schedule halves the bracket widths. Our test suite checks the engine against the first rows of every published 2026 table (for example $0–$7,500 at 0%, then 10% to $19,900 and 12% to $57,900 for single filers). Married filing separately uses the single schedule for withholding, exactly as the IRS tables do.

An existing exemption election on Form W-4 sets federal income-tax withholding to zero, including extra withholding. The calculator ignores inactive W-4 adjustments while preserving them in the form. FICA and state deductions remain separate; Alabama's formula responds to the changed federal-withholding deduction. Eligibility and certificate renewal are not determined here.

4. Social Security and Medicare (FICA)

Social Security = 6.2% × min(FICA wages, $184,500)
Medicare        = 1.45% × FICA wages + 0.9% × max(0, FICA wages − $200,000)

The 2026 wage base is $184,500 (SSA). Because the calculator assumes even pay through the year, it caps Social Security per period at the wage base divided by pay periods; a real payroll stops withholding once your year-to-date wages pass the base. The 0.9% Additional Medicare Tax is withheld above $200,000 regardless of filing status (IRS Topic 751).

5. State income tax

Most state tax calculations use an annualised income-tax estimate. Arizona, California, Georgia, Hawaii, Illinois, Indiana, North Carolina, Alabama, Kentucky, Maine, Maryland, Michigan, Minnesota and New Jersey use employer withholding methods, described below.

state taxable income = annual state wages − standard deduction − personal exemptions (self, spouse if joint, dependents)
state tax            = bracket schedule(state taxable income) − any deduction or exemption credits

The initial state data comes from the Tax Foundation's State Individual Income Tax Rates and Brackets, 2026 (as of January 1, 2026), with official sources and subsequent corrections listed on each state page. Married filing separately and head of household generally use the single schedule in these estimates; North Carolina and Alabama have separate deduction rules. Simplifications are stated on each state page: for example, Oregon's deduction for federal tax paid, Connecticut's and New York's benefit recapture, and Arkansas's low-income table are not modeled. Utah's taxpayer credit is modeled.

California: the California paycheck calculator uses EDD Method B, including the low-income exemption, printed pay-period deductions and credits, and separate DE 4 regular and estimated-deduction allowances. DE 4 status is independent of the federal W-4. Qualifying health-plan salary reductions reduce PIT and SDI wages; HSA salary reductions do not, so the calculator has a separate HSA input. Standard retirement deferrals reduce PIT wages but remain in SDI wages.

North Carolina: the North Carolina paycheck calculator follows the NC-30 annualized method. It uses the NC-4 filing status, allowances and extra withholding entered separately from the federal W-4. The state withholding rate differs from the income-tax rate; regular withholding is rounded to a whole dollar per paycheck, then the requested extra amount is added. This model covers regular wages, not NC-4 NRA adjustments, exempt certificates or separately paid bonuses.

Alabama: the Alabama paycheck calculator uses the employer formula with A-4 exemption codes and dependents. Its standard deduction and dependent exemption vary with annualized wages, and it deducts the federal withholding calculated for the paycheck before applying state brackets.

Kentucky: the Kentucky paycheck calculator uses the employer's annualized formula and adds the K-4 extra amount entered. It assumes withholding applies; reciprocity, military and other exemption cases are not modeled.

Maryland: the Maryland paycheck calculator uses the published pay-period percentage schedules, MW507 exemptions and county of residence. The Maryland line combines state and local withholding. County schedules follow the Comptroller's table links and may round the local component upward. Income-tier selection assumes annualized taxable pay from this job unless you enter a separate estimate.

Maryland table cells are checked against the same guide's annual schedules and adjacent bracket boundaries. Where printed cells conflict with that arithmetic, we use the consistent threshold, rate or base amount. Those corrections are recorded with the source document so they can be reviewed when the tables change.

Maine: the Maine paycheck calculator follows the revised August 2026 percentage method, with separate W-4ME status and allowances, a deduction that phases out as wages rise, the high-income surcharge and whole-dollar rounding before extra withholding. Annual tax-return deductions and credits are different.

Minnesota: the Minnesota paycheck calculator applies the 2026 employer computer formula to annual wages after $5,300 per W-4MN allowance. It selects the single or married chart and divides by pay frequency. The optional whole-dollar rounding applies before extra withholding; cents are used when that option is off. An existing Section 2 exemption affects state income-tax withholding only. The default is single with zero allowances.

Hawaii: the Hawaii paycheck calculator uses Booklet A’s annualized method: $1,144 per HW-4 allowance plus its $4,350 lump-sum payroll allowance, followed by the single or married table and any extra withholding. Head of household uses the single payroll table. The current HW-4 has two specific not-subject categories; the calculator does not determine eligibility or provide a general exempt election. Return deductions and tax rates are separate.

New Jersey: the New Jersey paycheck calculator uses the currently published NJ-WT percentage tables A–E. Separate NJ-W4 inputs select filing status, an optional line 3 table letter, allowances, extra withholding and an existing line 6 exemption election. Allowances use the printed pay-period amounts. Tax is rounded to cents; wages are not rounded to whole dollars. The default is single, table A and one allowance. An exemption affects NJ income-tax withholding only.

New Jersey’s printed table bases and thresholds are retained. The source import records two corrections: a thousands separator in D/quarterly and a one-dollar gap between E/monthly bands, reconciled with the adjacent threshold. Some older worked examples in NJ-WT differ slightly from the currently linked percentage tables. State wage allocation, reciprocity and separately paid bonus methods are outside this model.

Michigan: the Michigan paycheck calculator uses the 2026 Form 446 direct percentage method: 4.25% after $5,900 per MI-W4 exemption, with independent certificate and extra-withholding inputs.

Georgia: the Georgia paycheck calculator uses the June 2026 percentage method at 4.99%, with the printed pay-period standard deduction and allowance. G-4 C uses the one-working-spouse joint deduction; A, B and D use the smaller deduction. Line 7 total allowances and line 6 extra withholding are independent of federal W-4 entries. A qualifying line 8 election sets Georgia withholding to zero. Annual projections use the current rules throughout, without reconstructing early-2026 withholding or applying overtime/tip return deductions automatically.

Arizona: the Arizona paycheck calculator applies the A-4 percentage election to gross taxable wages, generally federal W-2 box 1 wages after eligible pre-tax deductions. The default is 2%; the seven positive options run from 0.5% to 3.5%. Extra dollars are added per paycheck. A qualifying box 2 election sets Arizona withholding to zero, including extras. Return standard deductions and dependent credits do not reduce the paycheck wage base. The displayed Arizona rate is the selected withholding rate, separate from the 2.5% annual income-tax rate.

Illinois: the Illinois paycheck calculator uses the 2026 IL-700-T automated formula: 4.95% after $2,925 per basic IL-W-4 allowance and $1,000 per additional allowance, divided by pay frequency. Line 3 adds extra dollars. A qualifying IL-W-4 exempt election certifies both federal and Illinois exemption; IL-W-5-NR instead exempts Illinois withholding only. Home-state withholding, certificate eligibility and interstate wage allocation are outside the estimate. The wage-range table method can produce small differences.

Indiana: the Indiana paycheck calculator uses Departmental Notice #1. It calculates and rounds the deduction constant for each WH-4 line separately: personal exemptions, additional dependents, first-time children and adopted children. State withholding and county withholding then use that adjusted pay and are rounded separately. January 1 residence takes priority over principal workplace. A qualifying WH-47 certificate removes state withholding only; WH-4MIL removes both Indiana taxes. Federal exemption does not remove Indiana withholding. Temporary waivers, interstate wage allocation and catch-up amounts are outside the model.

6. Local income tax

Maryland's county selector feeds its combined withholding calculation; local tax is not added a second time. Most other local estimates apply the rate to state wages after eligible pre-tax deductions. Kentucky's Louisville and Lexington presets instead use gross wages, including employee retirement and Section 125 salary reductions, with an optional taxable-pay override. Other local bases and exclusions can vary.

Indiana's county line is calculated by its WH-4 method after all four deduction constants. The two January 1 county selectors use the published 92-county schedule. No county tax or county extra is included when neither January 1 location is in Indiana. Annual output projects the selected rate schedule across steady paychecks; it does not combine schedules across a rate change.

Philadelphia presets also use gross employee wages before employee retirement and Section 125 deductions, following the city’s published guidance. The payment-period choice selects the applicable resident or nonresident rate. Custom Pennsylvania rates keep the state-wage basis unless you enter an override, even if the custom percentage equals a Philadelphia rate. Annual figures apply the selected rate throughout a steady-pay year; they do not combine January–June and July–December rates or determine refunds and credits.

Detroit city presets use 2.4% resident or 1.2% nonresident rates and the printed city exemption amounts. Grand Rapids uses a percentage estimate at 1.5% or 0.75%, with a $600 annual exemption; it does not reproduce wage-bracket tables. City wage allocation occurs before exemptions. Two-city credits and withholding applicability are outside the estimate.

7. State payroll programs

Employee-paid programs are included as separate lines where the 2026 rate is verified: Alaska, California, Colorado, Connecticut, Hawaii, Maine, Massachusetts, Minnesota, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Washington. Maine uses covered wages after qualifying Section 125 benefits and lets you adjust the employee contribution rate when your employer pays part or all of it. Each line's rate, wage base and source are in the state's data file and listed under Sources on its page. Programs whose 2026 parameters we could not fully verify are named on the page but not deducted.

Minnesota Paid Leave: the estimate includes up to 0.44% of covered gross wages, including voluntary retirement and cafeteria-plan salary reductions, on the first $185,000 in 2026. The cap follows the program’s rounding rule. Adjust the employee rate when your employer pays more. This full-year average does not track year-to-date wages or determine minimum-wage adjustments, private-plan terms or benefit eligibility.

Alaska UI: the employee rate is 0.50% on reportable wages up to $54,200 in 2026. Employer-plan retirement and qualifying medical benefits are excluded; dependent-care benefits remain reportable. Separate medical, dependent-care and employee Roth-plan inputs preserve those differences. Roth amounts remain in federal/FICA wages and are deducted from net pay once as after-tax contributions. The model assumes covered employment and steady full-year pay.

Hawaii TDI: the estimate is limited to the selected employee rate on weekly covered wages, $7.50 per week and half the entered total weekly premium. Ineligible employees have no deduction. Until you supply the plan premium and any covered-wage adjustment, the result is an upper estimate based on gross weekly pay. Benefit-specific wage exclusions and eligibility are not inferred. Weekly amounts are projected over 52 steady-pay weeks and divided by pay frequency.

8. Rounding

Intermediate amounts generally retain precision. North Carolina and Maine regular withholding are rounded to whole dollars per paycheck; Minnesota follows the rounding option selected. Arizona, California, Georgia, Hawaii, Illinois, Indiana, Michigan and New Jersey withholding is rounded to cents in the model, as are the Detroit and Grand Rapids preset estimates. Indiana also rounds each WH-4 deduction constant before adding them. Other line amounts are rounded for display. Employer rounding and payroll methods can still produce differences.

Paycheck forms require a value for active pay and hours fields. Invalid numbers and fractional allowance counts clear the calculated amounts until corrected. Zero is accepted; blank adjustments count as zero unless a different default is stated. Inputs that do not apply to the selected mode or election are ignored. Requests with deductions exceeding available pay are flagged, and Copy summary is enabled only for a valid calculation.

Tax-year calculators

The federal income tax calculators estimate the tax on Form 1040 for ordinary income:

taxable income = income − pre-tax contributions − max(standard deduction, itemized deductions)
tax before credits = bracket schedule(taxable income)
Child Tax Credit   = $2,200 per qualifying child + $500 per other dependent,
                     reduced by $50 per $1,000 of income above $200,000 ($400,000 joint)
income tax         = max(0, tax before credits − Child Tax Credit)

Long-term capital gains rates, the alternative minimum tax, refundable credits and above-the-line deductions other than the ones you enter are out of scope, and the page says so.

Money calculators

Each finance calculator states its formula on its own page. Compound growth uses the standard future-value formulas with the compounding frequency you pick; loan payments use the amortisation formula; payoff calculators simulate a stated monthly payment schedule. Actual lender day-count and payment-posting rules can differ. None of them apply tax unless the page says so.

The savings calculator places deposits at the selected intervals and applies equivalent growth between those times. APY is used directly; a nominal rate is converted using its compounding frequency. Calendar dates, bank posting rules, taxes, fees and rate changes are outside the projection.

The CD calculator also distinguishes APY from a nominal interest rate. Its term is months divided by 12, with interest retained to compound; actual bank day-count and payout terms may differ.

The Roth IRA calculator adds contributions at year end and compares two hypothetical tax timings: tax on positive growth each year, or tax on positive gains when sold. Neither scenario grants a credit for losses. It does not determine contribution eligibility or whether a withdrawal is qualified.

The dividend calculator tracks fractional share purchases, reinvested dividends and cash payouts separately. Forward yield on cost uses next-year projected dividends divided by all modeled share purchases, including reinvestment. Figures are before tax and fees.

The hours worked calculator totals whole minutes in one workweek before calculating pay. It assumes the entered rate is the applicable regular rate and applies 1.5 times that rate above 40 hours. Daily overtime, bonuses, special rules, overlapping shifts and calendar changes are not modeled.

The PayPal fee calculator uses reviewed US/USD presets and a stated cent-rounding model. It calculates the fee before net proceeds and finds the smallest cent-denominated payment meeting the target under that model. Actual account terms and fee rounding may differ.

What we do not do

• Calculator entries and results stay in your browser. Calculate buttons are enabled only after the client handler is ready, so unavailable calculator scripts do not fall back to sending inputs in a form URL. Usage analytics are described in our privacy policy.
• We do not give tax advice. The numbers are estimates for planning; your payroll department, tax software or a professional has the final word.
• We do not silently change numbers. Every data file carries the date it was verified and the sources used, and the date appears at the bottom of each page.

Update schedule

Federal figures are updated when the IRS publishes the next year's Revenue Procedure (usually October) and Publication 15-T (December). State figures are refreshed in January and whenever a state enacts a mid-year change. Each calculator lists its source review date.