Simple tools to help you plan your money: find your Coast FIRE number, see compound interest grow, pay off debt faster, hit savings goals, and more.
Every calculator is free and runs right in your browser. These are educational tools, not financial advice.
Type your own numbers — results update as you type.
Coast FIRE is the amount you need invested today so that growth alone — with no more contributions — gets you to a full retirement fund by retirement age.
See how steady contributions plus compound growth add up over time. Interest is compounded monthly.
Enter a balance, its APR, and a fixed monthly payment to see when you would be debt-free and what it costs in interest.
How long until you reach a savings goal with steady monthly deposits and a little interest?
See how much interest and time an extra monthly payment can save you over the life of a loan.
Turn an hourly rate and a few hours a week into weekly, monthly, and yearly numbers — and see how fast it can fund a savings target.
One digital template of ours, plus two widely recommended Amazon picks that fit this site's topics. The Amazon links are affiliate links — see the disclosure below.
A ready-to-use spreadsheet budget template with built-in debt payoff and savings goal tracking — the companion to the free calculators above.
Buy the budget template — $12 on Gumroadby Morgan Housel. A widely praised book of short stories about how people actually behave with money — a natural next read after using the calculators above.
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An undated paper budget planner and bill organizer for people who like tracking money on paper. It is a best seller in Amazon's Account Books category.
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Short, plain-English explainers for the ideas behind the calculators.
Coast FIRE starts with a simple question: how much would you need invested today so that, even if you never added another dollar, compound growth would carry it to a full retirement fund by the time you retire? That amount is your Coast FIRE number. Once your investments reach it, you have technically "coasted" — your retirement savings are on autopilot.
The math works backwards. First, figure out your full retirement target: your desired yearly spending in retirement divided by a safe withdrawal rate (4% is the classic example — $40,000 of yearly spending means a $1,000,000 target). Then discount that target back to today using your expected investment return and the years you have left until retirement. The younger you are, the smaller your Coast FIRE number, because growth has more time to do the heavy lifting.
People like Coast FIRE because it reframes the goal. Instead of "I need a million dollars," it becomes "I need a much smaller amount invested early, and then I mainly need to cover my living costs." Hitting your Coast FIRE number does not mean you can retire today — it means you could stop contributing to retirement accounts and let time finish the job. Try it in the calculator above with your own numbers.
The 50/30/20 rule is a simple way to split your after-tax income into three buckets: about 50% for needs (rent, groceries, utilities, minimum loan payments, insurance), about 30% for wants (eating out, entertainment, travel, hobbies), and about 20% for savings and extra debt payoff (emergency fund, investing, and paying debts down faster than the minimum).
To try it, add up one month of spending and sort it into the three buckets. Many people discover their needs bucket is well over 50% — that is common in high-rent areas and does not mean you have failed. The rule is a compass, not a law: if your needs are 65%, you might aim for 65/20/15 and nudge the savings slice up over time as income grows or debts disappear.
The real value of the rule is that it gives every dollar a rough job and turns "am I doing okay?" into a quick monthly check with three numbers. Any split you can actually stick to beats a perfect plan you abandon in month two.
If you have several debts, these are the two best-known ways to decide which one to attack first while keeping up the minimum payment on everything. With the avalanche method, you throw every spare dollar at the debt with the highest interest rate first. With the snowball method, you attack the smallest balance first, no matter the rate.
On pure math, the avalanche wins: paying the most expensive debt first means you pay less total interest and usually get debt-free sooner. Our debt payoff calculator shows what interest does to a single balance — across several debts, rate really does matter.
So why does the snowball exist? Because motivation matters too. Knocking out a small debt completely — closing an account, seeing a zero — feels like progress, and that momentum keeps many people going. The best method is the one you will still be following in six months: avalanche if the numbers motivate you, snowball if early wins keep you in the game.
This site is a small collection of free personal-finance calculators and short guides, built to make money math less intimidating. The focus is practical planning: retirement savings targets, the cost of debt, savings goals, mortgage payoffs, and what a side hustle can realistically add up to.
Everything here is free to use, needs no account, and runs entirely in your browser. If a calculator or guide helps you, the Tools & Templates section above is how the site supports itself.
Questions or feedback — reach out via the TikTok mentioned in the footer. Suggestions for new calculators are welcome.
This site has no accounts and no sign-ups. The calculators run entirely in your own browser — the numbers you type are never sent to or stored on a server.
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Recommendations here are selected for relevance to this site's topics — budgeting, debt payoff, and saving — and because they are widely regarded. The site owner has not necessarily used or read every recommended product, and a listing here is not a personal guarantee that a product is right for you. Please read a product's own page and reviews before buying.