Abel's Calculators

Should you put extra money toward your mortgage or invest it? How to compare the two paths by net worth impact — not just the interest rate.

The right answer depends on your tax rate now vs later. Here’s the math, plus how a Roth conversion ladder works for early retirees.

Two portfolios with the same average return can have completely different outcomes. How sequence risk works and what to do about it.

Claiming early gets you more years of payments. Claiming late gets you a bigger check. The break-even math, the spousal survivor angle, and when the investment comparison actually matters.

Most people think being in the 22% bracket means paying 22% on everything. It doesn’t. Here’s how marginal rates, the standard deduction, and bracket stacking actually work — with real numbers.

Most runners skip base-building and go straight to speedwork. Here’s what the research actually says about easy running, the 80/20 rule, and how much mileage you need before starting a race plan.

Cash flow, cap rates, appreciation, and tax benefits across 30 US markets. Where should rental property investors look — and which cities are a money pit?

It’s not magic — it’s thousands of randomly generated futures, tallied up. Here’s the full mechanism, why average-return projections mislead, and how to read the results correctly.

A 1994 research paper became the foundation of most retirement planning. Here’s what it actually said — and why a single number isn’t enough to plan a retirement around.

Comparing your rent to a mortgage payment isn’t the right question. Here’s how to evaluate the real wealth impact of buying vs renting — including the opportunity cost most people skip.

EVs have lower running costs but higher sticker prices. The answer depends on how much you drive, where you live, and how long you keep the car.

Most refinance advice focuses on monthly savings. Here’s how to evaluate a refinance by its real impact on your net worth.