Paycheck / Salary Calculator

Pay frequency changes the arithmetic, not the salary

Weekly is 52 paychecks a year, biweekly 26, semi-monthly 24, monthly 12. Biweekly and semi-monthly are routinely confused and are not the same: biweekly pays every 14 days, so two months a year contain three paychecks; semi-monthly pays on fixed dates such as the 15th and last day, always twice. Anyone budgeting on "two paychecks a month" while paid biweekly is under-planning in ten months and over-planning in two.

The third-paycheck months

A biweekly schedule produces 26 pay dates but 24 monthly rent or mortgage payments. Twice a year an extra paycheck lands, and treating it as bonus money rather than as the smoothing it actually is is a common budgeting error. Working out which months those fall in for the current year is worth doing once in January.

Deductions are taken in a specific order

Pre-tax deductions come off first — retirement contributions, health premiums, commuter benefits — which reduces taxable income and therefore the tax itself. Taxes are calculated on what remains. Post-tax deductions such as Roth contributions, union dues and garnishments come off last. This ordering is why a 500 pre-tax contribution reduces take-home by less than 500, and a 500 post-tax contribution reduces it by exactly 500.

Withholding is an estimate, not the tax

Each paycheck's tax is computed as if you earned that amount all year. Irregular income, a mid-year raise, a bonus or a second job all break that assumption, which is why people who change jobs mid-year commonly under-withhold. A large refund is not a win; it is an interest-free loan to the tax authority that could have been in your account monthly.

Bonuses are withheld differently

Supplemental income is often withheld at a flat statutory rate rather than at your marginal rate, which is why a bonus can arrive taxed far more heavily than expected. This is a withholding rule, not a tax rule — the difference is settled when the return is filed.

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