Rules inside the plan
Money Rules Hub
Use money rules as quick checks inside your Roadmap: budget splits, compounding time, emergency fund targets, savings rate, retirement withdrawal assumptions, debt load, and car affordability. Each rule remains an educational estimate, not advice.
- Calculator-backed rulesFormula shown on page
- Fast gut-checksSanity-check the Roadmap
- Learn the whyRules explained simply
Educational tools only
This website provides calculators, educational tools, and general personal finance information. Results are estimates based on user-provided assumptions and are not financial, investment, tax, legal, or insurance advice.
Read the full disclaimer
This website provides calculators, educational tools, and general personal finance information. Results are estimates based on user-provided assumptions. This website does not provide financial, investment, tax, legal, or insurance advice. Please consult a qualified professional before making important financial decisions.
50/30/20 Rule Calculator
GlobalSplit monthly income into needs, wants, and savings using the beginner-friendly 50/30/20 budgeting rule.
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70/20/10 Rule Calculator
GlobalSplit monthly income into living expenses, savings or investments, and debt repayment or giving.
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Zero-Based Budget Calculator
GlobalCheck whether your monthly income is fully assigned across expenses, savings, investments, and debt payments.
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Rule of 72 Calculator
GlobalEstimate how many years it may take money to double at a given annual return, or the return needed for a target doubling time.
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Rule of 114 Calculator
GlobalEstimate how long money may take to triple at a selected annual return.
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Rule of 144 Calculator
GlobalEstimate how long money may take to quadruple at a selected annual return.
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100 Minus Age Rule Calculator
GlobalEstimate a basic equity and debt allocation using 100, 110, or 120 minus age with risk profile adjustments.
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Investment Doubling Calculator
GlobalProject whether an investment may double within your selected period and estimate the doubling year.
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Emergency Fund Calculator
GlobalEstimate a 3, 6, 9, or 12 month emergency fund target and current savings shortfall.
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Savings Rate Calculator
GlobalCalculate your savings rate from monthly income, savings, and investments.
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Financial Freedom Number Calculator
GlobalEstimate the investment corpus needed to cover annual expenses using a selected withdrawal rate.
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4% Rule Calculator
GlobalEstimate sustainable annual and monthly retirement withdrawals using the 4% rule or a custom withdrawal rate.
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Retirement Corpus Rule Calculator
GlobalEstimate an inflation-adjusted retirement corpus and monthly investment needed before retirement.
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Debt-to-Income Ratio Calculator
GlobalCalculate monthly debt-to-income ratio and understand the risk category.
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28/36 Rule Calculator
GlobalEstimate home affordability using the 28% housing and 36% total debt rule.
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20/4/10 Car Affordability Calculator
GlobalCheck whether a car purchase fits the 20% down, 4-year loan, and 10% monthly income rule.
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Debt Snowball vs Debt Avalanche Calculator
GlobalCompare debt snowball and debt avalanche payoff estimates for up to three debts.
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Financial Roadmap
Build the broader monthly money plan these rule checks support.
Finance Navigator
Use guided routing when you do not know which rule, calculator, or decision tool fits.
Learn
Learn the basics behind budgeting, saving, investing, debt, retirement, salary, and insurance.