MoneyMath

All 15 calculators

Full index. Each entry links to the calculator and, where one exists, to the cornerstone guide. Looking for a specific question? See the category overview instead.

FIRE Family

When can you stop working?

  1. Coast FIRE

    When can you stop saving and let compounding do the rest?

    Best if you want to know how soon further saving becomes optional.

  2. Standard FIRE

    The classic 25× expenses target — full retirement, today's spending.

    Best if you want a single all-in retirement number.

  3. Lean FIRE

    Minimal-expenses early retirement — $25–40k/yr lifestyles.

    Best if you'd trade lifestyle for an earlier exit.

  4. Barista FIRE

    Portfolio plus part-time income jointly cover expenses.

    Best if you want a downshift, not a full stop.

Income & Wealth

What you make. What you keep.

  1. Net Worth

    What you own minus what you owe. The single most honest snapshot of where you stand financially.

    Best when you want one number that captures the whole picture.

  2. Savings Rate

    How many years until FIRE? Mostly a function of one number — and it isn't your income.

    Best when wondering whether to optimize for raises or savings.

  3. True Hourly Wage

    Your real take-home rate after tax, work expenses, and commute time — not the rate on your contract.

    Best when deciding whether a raise, longer commute, or new job is actually worth it.

  4. Freelance Hourly Rate

    Working backward from a target take-home: what to charge clients after tax, business expenses, and unbookable hours.

    Best when setting freelance prices or comparing W-2 vs going independent.

  5. eBay Profit Margin

    Net profit per item after Final Value Fee, the per-order flat fee, shipping, and inventory cost. Plus the breakeven price for any listing.

    Best when sourcing inventory or pricing a reseller listing.

  6. Compound Interest

    Future value with periodic contributions and any compounding frequency. See the share of the final balance that's principal vs. interest earned.

    Best when projecting investments, savings goals, or seeing what time does to a regular contribution.

Debt & Costs

What things actually cost.

  1. Debt Payoff

    Snowball vs avalanche, side by side. See when you'll be debt-free and how much interest each method saves.

    Best when you have multiple debts and need a plan that closes the loop.

  2. Mortgage

    PITI monthly payment, total interest over the loan, PMI cost, and what the home actually costs you over 30 years.

    Best when shopping for a home or weighing 15- vs 30-year terms.

  3. Student Loan

    Standard, Extended, and Income-Based repayment plans side by side — including the forgiveness amount IDR pays at year 20.

    Best when deciding between paying off and IDR with forgiveness.

  4. True Cost of Car

    What a car actually costs per year and per mile after depreciation, fuel, insurance, and maintenance — not the sticker price.

    Best when deciding new vs used, or whether a second car is worth it.

  5. Lifetime Cost

    Total cost of a long-term obligation — child, pet, or anything else with recurring annual spend over years. Today's-dollars and nominal totals plus monthly equivalent.

    Best when planning whether to have a kid, get a pet, or take on any 10+ year commitment.

Don't see what you need?

We're adding calculators each month. Calculators on the roadmap include investment return, tax bracket, dividend yield, and Etsy seller fees. If you have a specific personal-finance calculation you want and we don't have it, subscribe to MoneyMath Weekly — replies go straight to a human and the most-requested ideas get prioritized.