Know your net worth.
Settle rent vs. buy.
See your debt-free date.

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No account or signup is required for any tool on DuckDollar. Open any calculator, enter your numbers, and get your result. We don't collect your personal data or store your inputs.

Your FIRE number is the total amount of money you need invested to retire and live off your returns indefinitely. The standard formula is: annual expenses divided by 0.04 (the 4% safe withdrawal rate). For example, if you spend $50,000 per year, your FIRE number is $1,250,000. Our FIRE calculator walks through this with your actual numbers.

The avalanche method has you pay off your highest-interest debt first, which saves the most money in interest over time. The snowball method has you pay off your smallest balance first, which creates quick wins and momentum. Our debt payoff planner shows both methods side by side so you can see the real-dollar difference for your specific situation.

Self-employed people owe both income tax and self-employment tax (15.3% on 92.35% of net earnings). You pay these quarterly — in April, June, September, and January. The rough rule is to set aside 25–30% of every payment you receive. Our freelancer tax estimator calculates your actual 2026 quarterly payment based on your income and deductions.

DuckDollar's calculators use the same publicly documented formulas as professional financial software. Every formula is shown on the tool's page so you can check the math yourself. These tools give you accurate estimates for planning purposes. They are not a substitute for advice from a licensed financial advisor for major financial decisions.

The safe withdrawal rate is the percentage of your retirement savings you can spend each year without running out of money. The most cited figure is 4%, based on the 1994 Trinity Study, which analyzed historical 30-year retirement windows. At 4%, a $1,000,000 portfolio supports $40,000/year in spending with a high historical success rate. More conservative planners use 3–3.5% to account for longer retirements.

Divide the Consumer Price Index of the year you want by the CPI of the starting year, then multiply by your amount. A dollar from 1995 has the buying power of about $2.09 in 2025. Our dollar value calculator runs that math on official BLS data for any two years back to 1913, and also checks whether a raise kept up with inflation.

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