Enter all income as gross, before taxes. Each dollar then runs the same path a real paycheck does: pre-tax deductions come out first, the effective tax rate applies to what's left, and the remainder is the take-home shown in the chart. Your monthly spending is paid out of a cash buffer — the same amount every month whether a big check landed or not. Surplus refills the buffer; once it reaches your target, the rest goes to goals and investing.

Deductions. Benefits are subtracted from your regular monthly paycheck, since that's where premiums come out in practice. The 401(k) percentage applies to base pay, commissions, and bonus, but not to RSU vests or ESPP purchases — most plans don't allow deferral from equity, though some do allow it from bonus and commission, so check your own plan. Annual contribution limits are not enforced here. Note that 401(k) money isn't spent — it's savings that happen before the money reaches you, and it sits on top of the "left over for goals" figure below.

About the tax rate. The default is a rough starting estimate built from three pieces: federal income tax, calculated using real progressive tax brackets for the filing status you select (not a flat guess); FICA (Social Security and Medicare), applied to gross pay minus benefits, since 401(k) deferrals reduce your taxable income but not your Social Security/Medicare wages; and state/local tax, which you enter yourself since it varies widely by state and several states have none. The blended result is still an estimate — federal brackets are approximate and adjusted annually by the IRS, and the calculation doesn't account for your deductions, credits, or the Additional Medicare Tax on high earners. The most accurate number is your own: take last year's total tax divided by total income and enter that. Applying one flat rate across all income also simplifies real life — supplemental withholding on bonuses and RSU vests is often below your actual marginal rate, which can leave a bill at filing even when each paycheck looked fine.

RSU and ESPP amounts are treated as cash at vest or purchase and do not model share price movement, sell-to-cover mechanics, or a decision to hold shares. ESPP assumes shares are sold at purchase; holding for qualifying disposition treatment changes both timing and taxation.

Not modeled: income growth, inflation, interest on the buffer, employer match, or irregular expenses. Streams are placed across the year according to the timing you select, with commission and RSU schedules offset from each other as they commonly are in practice. Results are hypothetical and illustrate the shape of a variable-pay year, not a prediction of any specific one.