Finance Calculator Guides
Articles that explain formulas, edge cases, and interpretation for finance calculators. Each guide links to the relevant tools so you can apply what you learn.
Compound Interest: The Math That Changes Everything (With Real Examples)
A comprehensive guide to compound interest: how it works, why time matters more than rate, and how to use it to build wealth or avoid debt traps.
Emergency Fund Calculator: How Much You Really Need (And Why)
A practical guide to emergency funds: how to calculate the right amount based on your situation, where to keep it, and when to use it.
Credit Score Impact on Loans: How Much It Really Costs You
A data-driven guide to credit scores: how they affect loan rates, the real cost difference between score ranges, and strategies to improve your score.
Investment Portfolio Basics: Asset Allocation for Beginners
A beginner-friendly guide to investment portfolios: how to allocate assets, why diversification matters, and how to build a portfolio that matches your goals and risk tolerance.
Mortgage Escrow Explained: How It Works, When It Changes, and What to Watch
A practical guide to mortgage escrow accounts: how they work, why your payment can increase unexpectedly, and how to estimate escrow changes accurately.
Mortgage Points: When to Buy, Break-Even Math, and Tax Implications
A comprehensive guide to mortgage discount points: how they work, when buying points makes sense, break-even calculations, and how they affect your taxes.
ARM vs Fixed-Rate Mortgage: A Decision Framework with Real Scenarios
A practical comparison of adjustable-rate vs fixed-rate mortgages: rate cap math, scenarios where each wins, and how to decide based on your timeline and risk tolerance.
The Refinance Term Reset Trap: Why Lower Payments Can Cost More
A deep dive into the refinance term reset trap: how refinancing into a new 30-year term can lower payments but increase total interest, with real examples and break-even math.
House Affordability: The Framework I Use (PITI, DTI, and +1% Stress Test)
A comprehensive, personal affordability framework: how I model PITI, debt-to-income, and a rate stress test so I don’t buy a house that only works on paper.
APR vs APY vs Nominal vs Effective Rate (and the 3 Traps I See Most)
A deep but practical guide to interest rate math: APR vs APY, nominal vs effective, compounding, and how to compare loans and savings correctly.
Inflation and Real Returns: The Retirement Math People Skip
A comprehensive investing lens: how inflation changes your real return, why “7% growth” can mislead, and how I scenario-test retirement plans.
Marginal vs Effective Tax Rate: The Explanation I Wish I Got Earlier
A clear, practical guide to marginal vs effective tax rates, brackets, deductions, and how to interpret tax calculator outputs without panic.
From Salary to a Budget That Works: A Simple Monthly System
A personal budgeting system: convert salary correctly, build fixed + variable buckets, and use a few numbers to stay consistent without guilt.
PMI Explained (and How I Think About Removing It)
A practical, personal guide to PMI: when it applies, how it changes your true monthly housing cost, and the safest way to think about removal timelines.
PITI + DTI: The Affordability Math That Keeps You From Becoming House-Poor
A comprehensive affordability guide: PITI, HOA, maintenance, DTI, and the +1% stress test—how I combine them to make a decision that still works later.
Rent vs Buy: The Decision Framework I Wish I Had (with Real Numbers)
A comprehensive, personal rent-vs-buy playbook: modeling horizon, opportunity cost, maintenance, and the 3 scenarios that changed my decision.
Refinance Break-Even: The Simple Math That Prevented a Bad Decision
A personal, numbers-first guide to refinancing: how I calculated break-even, stress-tested assumptions, and avoided optimizing the wrong metric.
Mortgage Calculator: First-Time Buyer Guide
Master mortgage calculations for smart home buying. Learn payment breakdowns, affordability limits, and insider strategies for getting the best deal.
Tax Calculator: Save Money on Returns
Navigate tax calculations with confidence. Learn income tax, sales tax, property tax calculations and discover strategies to minimize your tax burden.
Investment Calculator Mastery: Build Wealth Like a Pro
Master investment calculators to analyze returns, compare options, and build a profitable portfolio. Learn ROI, compound growth, and smart investment strategies.
How to Use a Compound Interest Calculator for Smart Investing
A practical walkthrough of compound interest calculators—see how your savings can grow and make smarter investment decisions.
How to Calculate a Car Loan (Without Getting a Headache)
A practical guide to understanding car loan calculations, from monthly payments to total costs. Learn how to make smart financing decisions.
5 Common Mortgage Calculator Mistakes That Cost You Thousands
Learn how to avoid costly errors when using mortgage calculators and ensure you get accurate payment estimates for your home purchase.
Compound Interest: The 8th Wonder of the World
Master the power of compound interest with our comprehensive guide and learn how to use compound interest calculators effectively.
Retirement Planning: How Much Do You Really Need?
Use retirement calculators effectively to plan your future and understand the key factors that impact your retirement savings.