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The math of investing, explained with numbers you can check. New articles linked to our calculators.

Aug 26, 2026

Compound Interest, Explained: How Small Monthly Contributions Become Life-Changing Money

The math behind the most powerful force in personal finance — with real numbers you can check on our calculator.

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Aug 26, 2026

DCA vs Lump Sum: Which Is Better?

Run the math on $60,000 invested all at once versus spread across a year — and what the constant-return model can and can't tell you.

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Aug 26, 2026

How Much Do I Need to Retire?

The two-number answer to retirement planning — what your savings grow to, and how much you can safely withdraw — with reproducible numbers and honest assumptions.

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Aug 26, 2026

How Much Do I Need to Save Each Month to Reach a Goal?

Work backwards from any target — $250k, $500k, $1M — to the exact monthly contribution you need, with numbers you can reproduce on our savings goal calculator.

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Aug 26, 2026

Monthly vs Daily Compound Interest: How Much Does Frequency Matter?

Does daily compounding meaningfully beat monthly? We run the real numbers on a typical savings plan — and the answer may surprise you.

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Aug 26, 2026

Understanding Your Loan Payment

The equal monthly payment hides a lot — why early payments are mostly interest, how term and rate change your total cost, and how to compare loans honestly.

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Aug 26, 2026

What Happens If You Invest $500 a Month for 10 Years?

The exact numbers on steady monthly investing — what $500 a month becomes after 10 years at 7%, and why the last few years do most of the work.

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Aug 26, 2026

What's My Real Investment Return?

Your account statement's "return" hides when you added money. Learn how to work backwards from what you invested and what you ended with to your real money-weighted return.

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