Methodology
How each calculator works, what it assumes and leaves out, and the official sources behind its numbers.
Taxes, limits and payments follow the IRS, the Social Security Administration and each state’s published rates, to the dollar where the rules allow. Long-range projections are estimates and are labeled as such. Each November, when the IRS publishes the next year’s numbers, every tool is checked and its date below changes.
2026 tax year · Checked Oct 24, 2026How the paycheck calculator worksTake-home pay is gross pay less pre-tax deductions, federal income tax withholding, Social Security, Medicare, state income tax and post-tax deductions.2026 tax year · Checked Oct 24, 2026How the 401(k) optimizer worksThe optimizer walks every paycheck of the year, at every job, in date order.Checked Oct 24, 2026How the mortgage calculator worksThe monthly payment is principal and interest from the standard amortization formula, plus property tax, homeowners insurance, HOA dues and private mortgage insurance (PITI).Checked Oct 24, 2026How the FI/RE calculator worksYour FI/RE number is the savings that would pay your retirement spending, plus tax on it, at your withdrawal rate.2026 tax year · Checked Oct 24, 2026How the RSU planner worksEach grant becomes dated vests from its schedule, priced at today’s share price moved by your price scenario.2026 tax year · Checked Oct 25, 2026How the RSU tax calculator worksOne vest’s withholding, the way payroll runs it, against the tax the vest adds to your year: your tax with the vest less your tax without it.Checked Oct 24, 2026How the debt payoff calculator worksMonth by month, each debt gathers a month of interest and gets its minimum, the rest of your budget goes to one target debt, and each paid-off debt’s minimum rolls into the next..2026 tax year · Checked Oct 26, 2026How the comp tracker worksEach grant becomes dated vests, from its exact vest table when you have one or from its schedule.Checked Oct 24, 2026How the home affordability calculator worksThe highest price whose full monthly payment fits the 28/36 rule: housing at most 28% of gross monthly pay, and housing plus other debt payments at most 36%..2026 tax year · Checked Oct 24, 2026How the moving and state tax calculator worksTake-home in each state is your salary less federal tax, state income tax and Social Security and Medicare, on the same engine as the paycheck calculator.