finance
Finance
Mortgages, loans, savings, investing, debt payoff, retirement, and tax planning guides with worked examples.
Our Finance category covers the full spectrum of personal and business money management. Each article walks through a specific calculation — from compound interest and mortgage amortization to debt payoff strategies and retirement timeline planning. You will find the exact formulas, worked examples with realistic numbers, comparison tables, and direct links to the corresponding calculator tool. Whether you are evaluating a 30-year mortgage, comparing debt snowball versus avalanche methods, or projecting how much you need to retire, these guides give you both the understanding and the tool to run the numbers yourself.
32 articles in this category
Bond Yield Calculator: A Complete Guide to YTM & Absolute Returns
Master bond yield with step-by-step YTM calculations, current yield vs YTM, the inverse price-yield relationship, absolute return math, and practice problems with answers.
How to Calculate Bond Yield: A Complete Guide for Students & Investors
Current yield, YTM, YTC, yield to worst, and holding period yield — the full bond yield formula toolkit, plus clean vs dirty price, an Excel walkthrough, and 5 practice problems with verified answers.
Bond Duration & Interest Rate Risk Explained (Macaulay & Modified Duration)
Two bonds can share the same yield to maturity and still react completely differently when rates move. Duration is the number that tells you which one — with verified worked examples for Macaulay duration, Modified duration, and price sensitivity.
Treasury vs Corporate vs Municipal Bonds: Which Should You Buy?
Same word — "bond" — but three very different risk, tax, and yield profiles. A side-by-side comparison with a verified taxable-equivalent yield walkthrough so you can compare all three on the same basis.
Bond Funds vs Individual Bonds: Which Is Right for You?
Individual bonds return your principal at maturity. Bond funds never mature at all. That one structural difference explains almost every other tradeoff — with a verified expense-ratio drag example and a diversification cost comparison.
FIFO vs. LIFO for Crypto Taxes: How Tax-Lot Method Changes Your Gain
The same crypto sale can produce very different taxable gains depending on which purchase lot you treat as sold. A worked FIFO vs. LIFO example, plus the 2025 rule change that limits how freely you can pick.
How Crypto Portfolio Rebalancing Works (With a Worked Allocation-Drift Example)
Your target allocation does not stay put just because you did not trade. A worked example showing exactly how much a single coin's rally can drag a portfolio out of balance — and how to calculate the trade that fixes it.
Loan-to-Value Ratio: LTV Formula, Equity, and PMI
Learn how to calculate loan-to-value ratio, why lenders use LTV, how equity works, and how the DTC LTV calculator interprets the result.
Car Lease vs Buy: Financial Analysis and Calculator
Compare leasing and buying a car using total lease cost, amortized buy cost, residual value, mileage limits, fees, and ownership tradeoffs.
Loan Payment Guide: Formula, Interest, and Total Cost
Learn how fixed loan payments are calculated, why term length changes total interest, and how the DTC loan calculator matches amortization math.
Credit Card Payoff: Payment, Interest, and Strategy
Estimate credit card payoff time and interest, compare higher payments and transfers, and understand the limits of the DTC monthly payoff model.
Student Loan Repayment Plans: 2026 Comparison Guide
Compare fixed-term student loan math with current federal repayment resources, changing 2026 rules, total cost, and forgiveness verification steps.
Auto Loan Financing: Compare Payment and Total Cost
Compare auto financing by amount financed, annual rate, term, monthly payment, and total interest, then include ownership costs outside the loan.
Home Affordability: Budget, Formula, and Calculator
Estimate a home-price range from income, debt, down payment, rate, taxes, and insurance, then test costs the DTC model does not include.
Tax-Advantaged Accounts: 2026 Rules and Comparison
Compare 401(k), IRA, HSA, and 529 tax treatment, review 2026 federal limits, and understand what DTC account calculators assume.
Simple vs Compound Interest: Linear Growth vs Interest on Interest
Compare simple interest and monthly compound interest, learn when each model fits, and use worked examples aligned to the calculators.
Inflation-Adjusted Salary Growth: Real Raise Formula and Calculator Guide
Learn how to convert a nominal raise into real salary growth after inflation, using the same formula as the salary inflation calculator.
Emergency Fund Planning: How Much Cash to Keep
Build an emergency fund target from essential expenses, risk level, current savings, and monthly contributions using calculator-aligned math.
Rent vs Buy Guide: Compare Ownership Cost, Flexibility, and Break-Even Risk
Use a cost-first framework to compare renting and buying, including mortgage cost, taxes, insurance, maintenance, HOA, and down-payment opportunity cost.
Capital Gains Tax Guide: Basis, Selling Costs, and After-Tax Sale Proceeds
Estimate taxable gain more accurately by separating sale price, adjusted basis, selling costs, tax assumptions, and after-tax proceeds.
Dividend Investing Guide: Yield, Growth, Safety, and Ex-Dividend Basics
Learn how dividend income is estimated, why yield alone can mislead, and how growth, safety, taxes, and ex-dividend timing affect real income planning.
Inflation and Savings Guide: Purchasing Power, Real Return, and Cash Drag
See how inflation erodes purchasing power, why nominal gains can mislead, and how to use DTC calculators for real-return planning.
401(k) vs IRA Guide: Limits, Match, Taxes, and Contribution Order
Compare 401(k) and IRA contribution limits, employer match value, tax treatment, account control, and a practical savings order for retirement planning.
Side Hustle Tax Guide: Net Profit, Self-Employment Tax, and Cash Reserves
Understand how side hustle taxes start with net profit, when self-employment tax applies, and how to plan reserves, estimated payments, and pricing more realistically.
FIRE Planning Guide: FIRE Number, Timeline, Withdrawal Rate, and Reality Checks
Learn how FIRE planning translates spending into a target portfolio, how the DTC calculator estimates your timeline, and where early-retirement math usually breaks.
Down Payment Savings Guide: Cash Target, Closing Costs, and Timeline Planning
Build a realistic down payment plan by including closing costs, savings pace, PMI tradeoffs, and the cash cushion you still need after closing.
Compound Interest: Formula, Examples, and Calculator
Learn how compound interest works, calculate growth with monthly deposits, compare assumptions, and avoid common projection mistakes.
Mortgage Amortization Schedule: Formula and Guide
Learn how mortgage payments split between principal and interest, read an amortization schedule, and test loan terms with DTC calculators.
Debt Snowball vs Avalanche: Compare Payoff Methods
Compare debt snowball and avalanche payoff methods, see how ordering changes interest and timing, and model both with the DTC calculator.
Portfolio Diversification: A Practical Allocation Guide
Learn how asset allocation, diversification, correlation, costs, and rebalancing work, plus what a portfolio growth calculator can and cannot show.
Retirement Savings Timeline: Plan by Stage and Age
Build a retirement savings timeline, project contributions, test return assumptions, and review current U.S. account limits and planning gaps.
Mortgage Guide: Payment Formula, Costs, and PMI
Understand how mortgage payments work, what the DTC mortgage calculator includes, and how taxes, insurance, PMI, and loan term affect cost.
Explore other categories
Finance calculators
Popular finance calculators
Use these calculators alongside the guides above to run the numbers for your specific situation.
Mortgage Calculator
Calculate monthly mortgage payments including principal, interest, property taxes, PMI, and home insurance to budget your home purchase.
Loan Calculator
Calculate loan payments, total interest cost, and the full payoff schedule for personal, auto, or business loans in seconds.
Investment Calculator
Project compound growth of your investments with regular contributions, interest rate, and time horizon to estimate future value.
Retirement Calculator
Plan your retirement savings by estimating income targets, contribution needs, and growth so you can retire with confidence.
Savings Calculator
Forecast savings account growth and calculate the monthly deposits needed to reach a specific financial goal by a target date.
Debt Payoff Calculator
Compare debt snowball and avalanche payoff strategies and estimate exactly how long it will take to become completely debt free.
FAQ
Frequently asked questions
Which finance calculator should I use first?+
Start with the Mortgage Calculator if you are buying a home, the Loan Calculator for any type of borrowing, or the Investment Calculator to project long-term growth. Our Compound Interest Calculator is a great all-purpose tool for understanding how money grows over time.
How do I know if I can afford a home?+
Use our Home Affordability Calculator to estimate your budget based on income, debt, and down payment. A general rule is that your monthly housing costs should not exceed 28-36% of your gross monthly income.
What is the difference between simple and compound interest?+
Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal plus accumulated interest. Compound interest leads to exponential growth over time and is the standard for most investments and loans.