About these tools

These money calculators cover the questions people reach for a spreadsheet to answer: take-home pay after 2026 federal and state taxes, loan amortization schedules, solar panel payback periods, severance estimates, SaaS growth metrics, freelance day-rate math, and more. Each one uses standard financial formulas — the same logic behind textbook calculations — applied to current-year figures. Visit our guides for a deeper look at the methodology behind each tool.

All inputs stay in your browser. Nothing you type into the paycheck or invoice tools is sent to a server.

Common questions

• Are the tax and financial figures current?
  Yes. Tax brackets, FICA rates, and contribution limits are updated for the current year. The guides page explains which figures each tool uses and how to adjust for your situation.
• Is my financial data private?
  Completely. Every calculation runs locally in your browser — your salary, loan amounts, and invoice figures are never transmitted or stored anywhere outside your device.