Financial Calculators

Damodaran's SpaceX valuation, the DCF method, and an interactive 'what has to be true?' explorer. Why valuation is worth learning but stock-picking rarely beats indexing.

A bedtime-story joke portfolio that eats small-cap value, bonds, gold, T-bills, and trend. Over 10 years it earned less than 60/40, with half the drawdown.

A 60/40 looks diversified, but equities can drive 90% of its risk. What risk parity really is, whether to lever it, and when it beats a simple Bogleheads portfolio.

36% VTI, 24% VXUS, 40% AVGV: a Boglehead core with a global value tilt. The X-Ray, the equity style box, the evidence, and an interactive tilt explorer. Who it fits and who it does not.

Your broker's default cost-basis method silently picks your taxable gain. Learn SpecID, FIFO vs HIFO vs average cost vs MinTax, and how lot selection cuts the tax when you sell or rebalance.

Is $1 million enough to retire, or is $3 million the new benchmark? See how withdrawal rates, Social Security, FIRE math, inflation, and spending flexibility set your real number.

Yes, count your home and cars in net worth, but not in your FIRE number. Learn the four-net-worth framework, how home equity funds retirement, and the house-rich, cash-poor trap.

No, you do not need a paid-off home to retire, but you need durable, flexible cash flow. How a mortgage affects sequence risk, taxes, and FIRE math, with a keep-vs-payoff calculator.

A rumored DFA sale is no reason to panic-sell, but it exposes a risk DIY investors miss: fund-sponsor and strategy-drift risk, plus the tax lock-in of bespoke factor ETFs in taxable accounts.

The most heavily marketed financial products are often the most profitable for the seller. Learn the five marketing tactics, six risk lenses, and a hurdle calculator to evaluate any product.

Where the down-payment cash comes from changes the tax and liquidity cost more than the monthly payment. Compare selling appreciated stock, a family gift, and a family loan for a high-income tech buyer.

Half of Americans can't afford a $400 emergency? The Fed's 2025 data says 63% would pay it with cash. Here's what it really shows, and how to build true liquidity.

Should grandparents open their own 529 or fund a parent's plan? See the state tax math, new FAFSA rules, gift tax limits, and a multi-state case study.

Robinhood now lets an AI agent trade a dedicated account. The investing evidence on agentic trading, the conflict of interest, and who it actually fits.

A cash-secured put is a conditional buy commitment, not free yield. The Micron case, the index put-writing evidence, the tax math, and who it actually fits.

A WSJ opinion piece says wealthy investors should hold 90% stocks and 10% cash. A portfolio researcher asks: why not add Treasury futures on top? The evidence for and against each approach.

Many high-asset retirees never draw down principal. FIRE optimizes for safety, Die With Zero for memories. Here is a third path that funds both.

Volatility describes how returns vary. Pain describes how it feels to live through them. Learn when each risk metric matters: standard deviation, max drawdown, time underwater, Pain Index, and Ulcer Index, with a side-by-side calculator using 98 years of Damodaran return data.

AUM is not inherently bad, and hourly is not inherently good. Learn the three dimensions investors confuse (fiduciary, compensation source, billing method), what the academic evidence actually shows, and where commission-driven sales models like Edward Jones fit. Includes an interactive Advisor Fee Compass.

Answer 7 questions and see where you are on the 7-camp climb from budget to summit. A modern, personalized take on the r/personalfinance flowchart with 2026 IRS limits and Summitward tool deep-links.

Bill Bengen calls inflation the greatest enemy of retirees. The math is sharper: unexpected inflation alongside an early bear market breaks the 4% rule. Replay every historical 30-year retirement window.

Stop-loss orders feel like portfolio insurance. The evidence says they usually aren't. What stops do, what they don't, and when they actually help.

MBDR dollars before 59½ live in three places: after-tax 401(k), Roth 401(k), Roth IRA. Each has its own ordering rules, 5-year clocks, and penalty math. Walk through your own numbers with the simulator.

Buying is the easy half. Selling a lucky winner means navigating taxes, anchoring, regret, and concentration. What the evidence supports.

Donating appreciated stock is tax-efficient. A DAF can be a useful wrapper. Neither makes charity free. The mechanics, the 2026 OBBB changes (0.5% AGI floor, 35% deduction cap, $1k/$2k non-itemizer cash), and an after-tax cost calculator.

A viral tweet imagines putting your entire net worth into Treasury bonds and living off the coupons. The math is seductive and the implementation is mostly wrong. After-tax-real income, TIPS, I-bonds, and an interactive calculator that shows what the coupon actually buys.

AVGV bundles a global value, profitability, and smaller-cap tilt into one ETF that rebalances itself. A deep-dive review and a calculator comparing AVGV to a DIY basket of Avantis ETFs.

A trillion-dollar IPO with a 5% public float is not the same as a trillion-dollar IPO with 90%. Free-float adjustment, seasoning rules, and the methodology differences between CRSP, S&P 500, and Nasdaq-100 decide how much exposure your index fund actually takes. Includes a Mega-IPO Index Impact Calculator.

Direct indexing is heavily marketed to high earners, but ETF tax-loss harvesting already captures most of the value for many. A skeptical primer comparing ETF TLH, long-only DI, and long/short TALS, with an interactive decay visualizer.

At 5.03% nominal and 2.74% real on May 12 2026, Treasury and TIPS yields set the hurdle every risky asset has to clear. The framework, the common mistakes, and a Hurdle Rate Check calculator.

HML is the academic version of value investing: a transparent, rules-based long-short factor that asks whether cheap stocks outperform expensive ones. What the evidence says, how it differs from AQR and Avantis, and a Value Tilt Pain Test calculator.

TIPS ladders convert savings into guaranteed real cash flows. With 30-year real yields at 2.66% in May 2026, a ladder funds a 4.8% real payout. Who it is for, who it is not, the tax gotcha, and a calculator.

The 2010 $75k plateau was an oversimplification. PERMA-V, time affluence, and how to use your portfolio to fund a good life, not just to maximize net worth. Includes a Time Affluence Calculator.

Elroy Dimson's Rational Reminder interview, distilled. Easy data bias, U.S. exceptionalism, the GDP-vs-returns gap, and a stress tester that shows how much your plan depends on the equity risk premium.

Some employers now let you swap future equity for fixed cash on the same vesting schedule. It is a forward sale of single-employer exposure, not cash-now-vs-stock-later. With an interactive decision tool.

Most people expect investing to be about having an opinion. Systematic investing is about having a process. The evidence, the levels ladder, and the friction calculator that quantifies how small mistakes compound.

Vanguard's 1926-2009 data shows monthly, quarterly, and annual rebalancing produce near-identical risk-adjusted returns. The real questions are bands, cash flow, and taxes. With an interactive checker.

RSSY is not a high-yield ETF. It stacks U.S. equity exposure with a systematic futures carry strategy. Here is what futures yield actually is, what the prospectus discloses, and how the live track record compares to the S&P 500.

Farmland and timber are real asset classes, but the wrapper is the catch. See what platform fees, lockups, and taxes do to your net return vs. public REITs.

$47.5B in credit card rewards earned in 2024, but $160B in interest was paid. Where rewards fit in a plan, who should optimize, and who should not.

Dividend yield misses most of how US companies actually return cash. Boudoukh-Michaely-Richardson-Roberts (2007) showed net payout yield (dividends + buybacks - issuance) has stronger predictive power. With a Net Payout Yield Decomposer.

The US is 26% of global GDP and 63% of MSCI ACWI. Ritter (2005) found cross-country GDP-equity correlation is negative. Five links separate GDP from per-share return, and a GDP-to-Stock-Return Bridge calculator walks every one.

The Fed sets one rate (FFR target). Everything else is markets. The yield curve = expected short rates + term premium, r-star is unobservable, mortgage rates aren't Fed funds + spread. With a Bond Duration Shock + Reinvestment Risk calculator.

Why the viral R² = 0.73 forward P/E vs. 10-year return chart looks more certain than it is. Rolling-window overlap, persistent regressors, and a Monte Carlo demo of spurious R²-with the BRW (2008), Stambaugh, and Goyal-Welch evidence behind it.

Account labels are wrappers; risk and return live at the household level. Reichenstein after-tax, Viceira human capital, the asset-location 80/20, and a Household X-Ray calculator with location flags.

Markowitz's portfolio choice for individual investors. Two-asset variance with correlation, the 'correlations go to one' supplement, the marginal-fund test, and a portfolio impact calculator.

How leverage relates to MPT and Sharpe, what Ayres-Nalebuff actually argued, FINRA Reg T and 25% maintenance, the margin-call drawdown formula, daily-reset path dependency, tax wrinkles, and a Margin Stress Test calculator.

The Fama-French RMW factor, Novy-Marx's gross profitability, out-of-sample evidence (Wahal, Linnainmaa-Roberts, Harvey-Liu-Zhu, McLean-Pontiff), the Avantis-vs-Dimensional cash-vs-operating disagreement, and a tilt + tracking-error calculator.

Nick Maggiulli's six wealth levels, the 0.01% rule, UBS distribution data, and the liquidity / age / geography corrections peer book reviews skip. With total-vs-liquid calculator.

TALS for HNW taxable investors: AQR's loss-capacity research, the gain-deferral surprise, Section 1259 caveat, SMA pass-through, and a hurdle calculator that refuses to estimate alpha.

JL Collins's FU Money is enough accessible wealth to refuse a bad deal without your life falling apart. Five autonomy levels, the Fed and Vanguard data, and a runway stress-test calculator.

AQR tested 196 buy-the-dip rules; most lost. Vanguard, Dimensional, PWL, and Morningstar agree. The empirical case for investing today, with a cost-of-waiting calculator.

Nick Maggiulli's accumulation rule, what it gets right, the savings-vs-returns crossover most peer posts miss, and which dollars it doesn't apply to. With calculator.

CAPE near 40 doesn't mean sell. It means lower your forward return assumptions. The academic evidence on valuation ratios as long-horizon return forecasts, the valid criticisms of CAPE, and an interactive calculator for your own assumptions.

Long-run stock history is relevant because it shows returns are regime-dependent, not because it produces a clean 6-7% real constant. McQuarrie's data corrections, the international evidence, the railroad case, and a calculator that compares terminal wealth across five historical regimes.

Most home affordability calculators ask if you can make the payment. This one asks if you'll still be solvent if your RSUs drop 40% and a repair hits.

Stocks lost to bonds for 20, 41, and even 68 years in a row. Your retirement plan needs to survive that scenario. Here's what 220 years of data show.

Trend-following managed futures can diversify across regimes, but they're not magic. Here's the evidence, the tradeoffs, and who should and shouldn't use them.

Covered-call ETFs distribute 8-12% per year while the underlying strategy earns far less. Here's the academic evidence, the tax drag, and who they actually fit.

A 30-year fixed mortgage can hedge inflation, but only conditionally. Here's the math, Bernstein's four deep risks, and when the framing breaks down.

Med, law, and MBA students often save little or borrow during school. Here's the academic case (Choi, Carroll), the risks, and the middle ground.

Return-stacked ETFs (NTSX, RSSB, RSST, SPLS) promise diversification without sacrificing equity. Here's the hurdle-rate framework for evaluating any of them.

Mega-IPOs from SpaceX to OpenAI are coming. Here's the academic evidence on IPO returns, the first-day-pop trap, and what indexers actually own.

58% of U.S. stocks since 1926 lost to Treasury bills lifetime. Just 4% account for all stock-market wealth. Here's why broad diversification wins mathematically.

Keeping up with inflation long-term is not hedging inflation when you need it. The real answer is explicit CPI-linked assets (I Bonds and TIPS) plus fixed-rate debt as the underrated liability-side hedge. Includes an after-tax real yield calculator.

The 3-6 month rule is lazy. BLS data shows unemployment duration varies by industry. A job-risk matrix and sizing calculator for your household's real income-shock risk.

Your RSUs are not taxed at 22%. They are often withheld at 22%. Use this per-vest calculator to project your real federal tax, pick the right election, and check IRS safe harbor before April.

Points are a prepayment of interest, not a rate hack. Learn the CFPB break-even framework, who should and shouldn't buy points, and why shopping lenders beats chasing a headline rate. Includes an interactive decision calculator.

VTI and VOO are 99% correlated with 87% overlap. VTI is the more principled choice. VOO is perfectly fine. The bigger mistake is obsessing over this decision instead of the ones that actually matter.

Insurance is for transferring catastrophic risk. Investing is for compounding capital. When a product tries to do both, you usually get more complexity, more fees, and more sales incentives. Here is the evidence.

Life insurance is a temporary hedge against catastrophic income loss. Use the needs-based calculator to find your coverage gap, learn why employer coverage is not enough, and why term almost always beats whole life.

Your mortgage payment is not your cost of ownership. Learn the three views (cash, economic, exit) used by HUD and CFPB, see the real categories most buyers underestimate, and use the interactive calculator to compute your own numbers.

Depreciation is usually the largest cost of car ownership, and most buyers never see it. Learn the AAA/Edmunds TCO framework, see how gas, hybrid, and EV costs compare, and use the interactive calculator to find your real cost per mile.

Only 15% of HSA holders invest their funds. The rest are leaving the most tax-advantaged account in America sitting in cash. Here is the receipt hoarding strategy, the math, and who it is (and is not) for.

Your HYSA is costing you money in state taxes. SGOV, T-bills, and muni money markets often beat savings accounts after tax. Use the Cash Reserve Optimizer to size your emergency fund and find the best vehicle for each layer.

Single-earner married households can save $95,750 in tax-advantaged accounts in 2026; with two 401(k)s + Mega Backdoor access, the ceiling rises to $167,750. The math, the order of operations, and a calculator that handles single, dual-earner, and asymmetric cases.

Stop optimizing for total interest paid. The right down payment depends on cash to close, post-close reserves, PMI thresholds, and loan-bucket boundaries. Includes a calculator for tech workers with RSUs.

Fidelity's ZERO funds are fine investments. But '0.00% expense ratio' draws attention to the least important basis points while hiding proprietary benchmark risk and narrower market coverage.

Claiming at 62 vs. 67 vs. 70 changes your lifetime benefits by hundreds of thousands of dollars. See the break-even math, three case studies, and how taxes complicate the simple answer.

Lump sum investing beats DCA 67% of the time. But the real question is when it doesn't. Explore 98 years of S&P 500 data with an interactive calculator and see which strategy won in every starting year since 1928.

The answer depends on one number: your break-even retirement tax rate. Use the interactive calculator to find yours, see 2026 brackets, and learn why tax diversification matters more than picking the 'right' account.

Your first 90 days as an investor. Prioritize spending, open the right account, pick two index funds, and let compounding do the heavy lifting. Evidence-based, no jargon, with an interactive compound interest calculator.

Calculate your personal FIRE number from your spending and safe withdrawal rate. Reference tables for FIRE numbers by spending level, a savings rate timeline chart, and three fully worked examples at different income levels.

Calculate your Coast FIRE number with step-by-step formulas, comprehensive tables by age, and three worked examples. Find out if you have already reached Coast FIRE and what to do next.

Compare the two most popular debt payoff strategies side by side. Learn the math behind avalanche and snowball methods, see how extra payments accelerate your timeline, and explore when investing beats paying off debt.

Learn how tax-loss harvesting works, from wash sale rules and capital loss netting to replacement fund strategies. See a worked example of the tax benefit calculation and understand when TLH is worth the effort.

Your FI number is the portfolio size that lets you stop working. Learn how to calculate it from your spending and safe withdrawal rate, and explore Lean, Comfortable, and Fat FI tiers.

RSU vests are taxable income that can push you into a higher bracket. Learn the sell-vs-hold framework, how to use tax-loss harvesting when diversifying, and the common mistakes engineers make with equity comp.