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Settle rent vs. buy.
See your debt-free date.
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Every tool is free, foreverFIRE Number Calculator
Find your FIRE number and retirement date across all 5 FIRE strategies.
Use this tool →Debt Payoff Planner
See exactly how much sooner you'd be debt-free with snowball vs avalanche.
Use this tool →Freelancer Tax Estimator
Enter your freelance income and see your total tax, quarterly amounts, and set-aside rate.
Use this tool →…or browse all 12
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Common questions
Are all tools on DuckDollar really free?
Yes. Every tool on DuckDollar is completely free to use with no account required, no trial period, and no features locked behind a paywall. We don't charge for anything and never will. The site is funded by non-intrusive advertising, not by charging users.
Do I need to create an account to use the calculators?
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.
What is a FIRE number and how do I calculate it?
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.
What is the difference between the avalanche and snowball debt payoff methods?
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.
How do freelancers calculate quarterly taxes?
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.
How accurate are these financial calculators?
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.
What is a safe withdrawal rate for retirement?
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.
Can I use these calculators on my phone?
Yes. Every tool on DuckDollar is designed mobile-first. All inputs are large enough to tap, text is readable without zooming, and results update instantly. No app download needed.