Calculators that show their work.

Project the growth of savings and investments with inflation-adjusted (real) returns, fees, taxes, contribution step-ups, and a full year-by-year breakdown.

CAGR, total return, and the true money-weighted return (IRR) when you add contributions — plus the inflation-adjusted real return.

Find how much to set aside each month to hit a target by a deadline — or how long your current pace will take.

What a lump sum and regular contributions grow to at any rate and compounding frequency — with the split between what you put in and the interest you earn.

The compound annual growth rate that links a starting and ending value over time — the single rate that makes investments of different lengths comparable.

Project dividend income with reinvestment (DRIP), rising payouts, and yield-on-cost — and see how much DRIP adds over taking cash.

Return on investment from what you put in and got back — plus the annualized (compound) ROI, the only fair way to compare investments held for different lengths of time.

Turn a nominal rate into its true APY, compare APY across compounding frequencies, and see the real dollars earned.

Monthly payment, full amortization schedule, the true lifetime cost of interest, and how extra payments shorten your loan.

Payment, total interest, and payoff timeline for any fixed-rate loan, with an amortization breakdown.

The real out-the-door cost — sales tax with the trade-in credit, fees, and the negative-equity timeline showing when you stop being underwater.

Whether refinancing pays off: the new payment, the break-even point on closing costs, and the term-reset interest trap.

Compare the snowball and avalanche strategies across all your debts — payoff order, total interest, and which one frees you sooner.

See how long a fixed payment takes to clear your balance — and how the shrinking minimum-payment trap costs you years and thousands in interest.

How much house you can afford using real front-end and back-end DTI ratios — and which one is actually limiting your budget.

Standard repayment vs an income-driven plan based on your discretionary income — the lower payment and the long-term tradeoff.

Model contributions, employer match, and withdrawals to see whether your nest egg lasts through retirement.

Your financial-independence number, years to reach it, your Coast FIRE figure, and savings rate — all in today’s money.

Project your 401(k) with the real IRS contribution limits and catch-up — and see the employer match you’re leaving on the table.

Project tax-free Roth growth within the IRS contribution limits, and see exactly how much the tax-free growth beats a taxable account.

After-tax retirement outcomes for Roth vs Traditional — including investing the up-front tax saving and your break-even tax rate.

Estimate your benefit with the real PIA bend-point formula, and see how claiming from 62 to 70 changes your monthly check.

Required minimum distributions using the real IRS Uniform Lifetime Table, projected across every year with the estimated tax on each.

Estimate your 2025 federal income tax with a bracket-by-bracket breakdown, FICA, and your true marginal vs effective rate.

Short- vs long-term tax compared, the dollar benefit of crossing the one-year mark, and your after-tax annualized return.

Tax across multiple crypto disposals — short vs long-term, loss netting, and the reminder that crypto-to-crypto trades are taxable.

See why a large gift almost never triggers tax — the per-recipient annual exclusion and the lifetime exemption, explained.

Lump sum vs annuity, after federal and state tax — compared on a present-value basis so you see which option really wins.

Powerball cash value vs the 30-year graduated annuity, after federal and state tax, compared on a present-value basis.

Convert any pay rate — hourly, daily, weekly, biweekly, semimonthly, monthly, or annual — into the equivalent at every other frequency, accounting for your real hours and weeks worked.

Convert an annual salary into the equivalent hourly wage, adjusting for the hours and weeks you actually work so the rate reflects your real schedule.

See what your hourly wage adds up to over a full year — and at every pay period in between — based on the hours and weeks you work.

Turn an hourly, weekly, or monthly rate into your true annual income, with your real hours and weeks worked factored in — not just a flat ×2,080.

Calculate your pay every two weeks (26 paychecks a year) from any rate — and see exactly how it differs from a twice-a-month semimonthly check.

Work out your gross monthly income from any pay rate — useful for budgets and rent or loan applications that ask for a monthly figure.

Find your gross margin from cost and price, or price a product to hit a target margin — with the markup, profit, and the margin-vs-markup distinction made clear.

Work out the markup on a product, or set a price from a target markup — and see why a markup is always a bigger number than the margin it produces.

Calculate gross profit margin from revenue and cost, see the dollar profit per unit, and price to a target margin — the number that protects your bottom line.

Return on ad spend from revenue and ad cost — plus the full funnel (CPM, CPC, CTR, conversion rate, CPA, ROI) so you see what is really driving the number.

Cost per thousand impressions from spend and impressions — with CPC, CTR, conversion rate, CPA, ROAS, and ROI for the same campaign in one view.

Your conversion rate from conversions and clicks — with cost per conversion, ROAS, and ROI so you know what each conversion costs and earns.

Click-through rate from clicks and impressions — alongside the rest of the funnel so you can tell whether a high CTR is actually converting.

Price European calls and puts with the Black-Scholes-Merton model — live Greeks, an implied-volatility solver, the profit-and-loss payoff at expiry, and the full working shown step by step. Educational, not trading advice.

Estimate intrinsic value by discounting projected free cash flows plus a terminal value back to today — with a per-year breakdown and how much of the value rests on the terminal assumption.

Find the return an investment should earn for its market risk with the Capital Asset Pricing Model — risk-free rate plus beta times the equity risk premium, broken down step by step.

Compute the weighted average cost of capital — the blend of the cost of equity and the after-tax cost of debt by their weights — the discount rate that powers a DCF.

The price-to-earnings ratio from share price and EPS (or net income and shares), plus the earnings yield it implies — the most-quoted valuation multiple. Educational, not investment advice.

Value a dividend stock with the Gordon Growth model — the present value of all future dividends from D₁ ÷ (r − g) — and see why the result is so sensitive to the spread between return and growth.

Price a bond from its yield, or solve the yield to maturity from a market price — with the premium/discount, current yield, and the cash flows behind the number. Educational, not trading advice.

Measure risk-adjusted return: the excess return over the risk-free rate per unit of volatility, with the calculation shown step by step. Educational, not investment advice.

Purchasing power in both directions, the cumulative erosion of a fixed sum, and the income you’d need to keep pace.

Map your real expenses into the 50/30/20 needs/wants/savings buckets, see which one you overspend, and find your savings rate.

How many months you’re covered today, a recommended 3–6 month target band, and how long it takes to get there at your pace.

Categorized assets and liabilities, your liquid vs illiquid split and debt-to-asset ratio, and a multi-year net-worth projection.

Compare two cities and find the salary you’d need to keep your standard of living — with a category-by-category breakdown.

Tip on the pre-tax subtotal (not the tax), split the bill any number of ways, round up, and compare common tip percentages.

Sale price and amount saved — including stacked discounts (which multiply, not add) and the real out-the-door price with tax.