Financial guides
Plain-English explanations of how every calculator works and what the numbers mean for your finances.
Taxes
How the US Income Tax Calculator Works — Brackets, FICA, and Take-Home Pay
Understand how federal and state income tax is calculated, how tax brackets actually work, and what FICA withholding means for your paycheck.
Take-Home Pay Calculator: What's Left After Taxes and Deductions
Understand what reduces your gross pay before it hits your bank account — federal tax, state tax, FICA, health insurance, 401(k), and more.
How Capital Gains Tax Works — Long-Term, Short-Term, NIIT, and State Tax
Learn the difference between short-term and long-term capital gains rates, how the Net Investment Income Tax applies, and how to calculate your total capital gains tax bill.
Self-Employment Tax: How the 15.3% SE Tax Works and How to Estimate Quarterly Payments
Understand self-employment tax, how to deduct the employer half, how to calculate quarterly estimated tax payments, and what deductions reduce your SE tax burden.
Roth IRA vs. Traditional IRA: Which Is Better for Your Retirement?
Compare Roth and Traditional IRA tax treatment, contribution limits, income limits, and withdrawal rules to determine which account type maximizes your retirement wealth.
W-4 Withholding Calculator: How to Fill Out Your W-4 and Avoid a Tax Bill
Learn how the W-4 form controls your paycheck withholding, how to calculate your correct allowances, and how to adjust withholding after major life events.
How to Lower Your Tax Bill: 12 Legal Tax Reduction Strategies for 2025
Discover 12 proven, legal ways to reduce your federal income tax bill in 2025 — from maxing out pre-tax retirement accounts to tax-loss harvesting, HSAs, and strategic deduction timing.
How the Paycheck Calculator Works — Federal Withholding, FICA, and Net Pay
Learn how federal income tax withholding, Social Security, Medicare, and pre-tax deductions combine to determine your net pay on any paycheck.
Loans & Mortgage
How a Mortgage Calculator Works — and What PITI Really Means
Learn how lenders calculate your monthly mortgage payment, what PITI includes, how PMI works, and how to use a mortgage calculator to compare loan options.
How an Auto Loan Calculator Works — Monthly Payments, Interest, and Sales Tax
Learn how car loan payments are calculated, how interest adds up over the loan term, and how sales tax affects your total cost when buying a vehicle.
What Is APR and How to Calculate It — The True Cost of Borrowing
APR (Annual Percentage Rate) tells you more than an interest rate alone. Learn how APR is calculated, why it differs from the interest rate, and how to use it to compare loans.
How the Home Affordability Calculator Works — The 28/36 Rule Explained
Learn how lenders determine how much house you can afford using debt-to-income ratios, and how to calculate your maximum home price based on your income and debts.
What Is Debt-to-Income Ratio and Why Does It Matter for Mortgages?
Understand front-end and back-end DTI ratios, how lenders calculate them, what the thresholds are for mortgage approval, and how to improve your DTI before applying.
First-Time Home Buyer Guide: Complete Step-by-Step Process for 2025
Complete first-time home buyer guide covering credit requirements, down payment strategies, mortgage types, pre-approval, making an offer, home inspection, closing costs, and first-time buyer assistance programs for 2025.
How to Refinance Your Mortgage — Break-Even, Closing Costs, and When It's Worth It
Learn how mortgage refinancing works, what closing costs to expect, how to calculate your break-even point, and when refinancing actually saves money.
Home & Planning
How the Compound Interest Calculator Works — The Math Behind Exponential Growth
Learn how compound interest grows your money exponentially, how contribution frequency affects your final balance, and how to use a compound interest calculator effectively.
How to Calculate Your Net Worth — Assets, Liabilities, and What the Number Means
Learn what net worth is, how to calculate it accurately by listing assets and liabilities, and how to use it as a financial health benchmark over time.
How the 401(k) / RRSP Planner Works — Project Your Retirement Savings
Learn how to project your 401(k) or RRSP balance at retirement, how employer matching works, and what contribution rate maximizes your long-term outcome.
How the Credit Card Payoff Calculator Works — Avalanche vs. Snowball Strategy
Learn how credit card interest compounds, how the avalanche and snowball payoff methods compare, and how to calculate your debt-free date.
Rent vs. Buy: How to Decide Using Real 30-Year Cost Analysis
Compare the true long-term cost of renting versus buying a home including equity, appreciation, maintenance, and investment opportunity cost to find your break-even year.
Student Loan Repayment Calculator: PAYE, IBR, SAVE, and PSLF Explained
Understand income-driven repayment plans for federal student loans, how monthly payments are calculated under PAYE and SAVE, and when PSLF makes sense.
Break-Even Analysis Explained — When Does a Big Purchase Pay for Itself?
Learn how break-even analysis works for refinancing, solar panels, buying vs. leasing, and any upfront cost with ongoing savings — and how to calculate your own.
The 50/30/20 Budget Rule Explained — And How to Apply It to Your Income
Learn how the 50/30/20 budgeting framework splits your after-tax income into needs, wants, and savings, and how to adjust it when your numbers don't fit the mold.
How Much Emergency Fund Do You Need? A Realistic Framework
Learn how to size your emergency fund based on your monthly expenses, employment type, and number of household earners, and where to actually keep the money.
How Much Should You Save Each Month to Hit a Financial Goal?
Learn the formula behind calculating required monthly savings for any goal, how compound interest changes the number, and which account type fits your timeline.
How to Calculate Home Equity — and What LTV Really Means
Learn how home equity is calculated, the difference between equity from appreciation and from paydown, what LTV ratio means for PMI and HELOCs, and how it builds over time.
International
How the UK Income Tax Calculator Works — PAYE, National Insurance, and Take-Home Pay
Learn how UK income tax bands work, how National Insurance contributions are calculated, and how to estimate your take-home pay using a PAYE calculator.
UK Stamp Duty Calculator — SDLT, First-Time Buyer Relief, and Additional Property Surcharge
Understand how UK Stamp Duty Land Tax is calculated, first-time buyer thresholds, the 3% additional property surcharge, and how LBTT works in Scotland.
How the Canadian Income Tax Calculator Works — Federal, Provincial, CPP, and EI
Learn how Canadian income tax is calculated across federal and provincial rates, how CPP contributions and EI premiums work, and how to estimate your net income.
How the Australian Income Tax Calculator Works — ATO Rates, Medicare Levy, and LITO
Learn how Australian income tax is calculated using ATO tax brackets, how the Medicare Levy applies, what the Low Income Tax Offset does, and how to estimate your take-home pay.
How the Irish Income Tax Calculator Works — PAYE, USC, and PRSI Explained
Understand how Irish income tax is calculated including PAYE rates, Universal Social Charge bands, PRSI contributions, and how to estimate your net income in Ireland.
How the New Zealand Income Tax Calculator Works — PAYE, ACC, and KiwiSaver
Learn how NZ income tax is calculated using Inland Revenue PAYE rates, how ACC earners levy works, and how KiwiSaver contributions affect your take-home pay.