Guides
Short educational articles that explain how concepts work and link to the calculators that apply them. Guides are published only when they answer a specific question accurately — not to increase URL count.
Published guides
Home & mortgage
How mortgage refinance savings are calculatedLearn how estimated refinance payment changes, remaining interest, and a simple payment break-even are derived from the loan assumptions you enter — and what those figures leave out.
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Debt & credit
Debt snowball vs avalanche: how the orderings differLearn how snowball and avalanche repayment orderings work, what they change in a month-by-month payoff model, and how to compare them with your own balances — without treating either as advice.
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Home & mortgage
How HELOC borrowing capacity is estimatedSee how estimated home equity and simplified HELOC borrowing capacity are derived from home value, mortgage balance, and an assumed maximum combined LTV — and why that is not an approval amount.
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Auto loans
How auto loan interest worksUnderstand how an educational auto loan estimate builds amount financed, applies a documented sales-tax assumption, and calculates fixed-rate monthly interest and amortization from the terms you enter.
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Planning & protection
How to estimate life insurance needsLearn how an educational DIME-style estimate combines debt, income replacement, mortgage, and education funding, then subtracts existing coverage and other resources you enter.
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Planning & protection
How retirement compound growth is calculatedSee how an educational retirement projection compounds monthly from contributions and an assumed return, applies optional contribution growth, and reports inflation-adjusted value — without guaranteeing outcomes.
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Debt & credit
How student loan amortization worksLearn how a standard fixed-rate student loan payment, interest, and schedule are estimated — and why income-driven or forgiveness programs are not invented when they are unsupported.
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Debt & credit
How credit card payoff time is calculatedUnderstand how months to pay off a card, total interest, and the final payment are estimated from balance, APR, and a fixed monthly payment — including when payoff is impossible under those assumptions.
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Related tools
Prefer jumping straight into a calculator? Browse the calculators index or open a tool below. Methodology notes live on methodology.