Everyday money math, made simple
Plain-language guides to severance pay, take-home salary, and taxes — each linked to a free calculator you can use right away.
Counting Days That Actually Matter: Notice Periods, Deadlines & Tenure
The real problem isn't subtracting dates — it's counting them the way contracts, courts, and HR do. Learn the inclusive/exclusive, business-day, and month-end traps that cause costly mistakes, and check any span with the date difference calculator.
Read the guide →Tool guidesHow Much House Can You Afford? The 28/36 Rule Explained
The 28/36 rule turns your income into a realistic home budget in two steps. See how much monthly payment — and how big a loan — your income supports, why the interest rate changes everything, and the costs the rule hides.
Read the guide →Tool guidesHow to Calculate a Percentage (3 Ways, With Examples)
Learn how to find a percent of a number, what percent one number is of another, and percentage increase or decrease — with clear examples. Check your answer with the free percentage calculator.
Read the guide →Tool guidesPay Off Debt or Invest? A Clear Way to Decide
Have spare cash? Whether to pay down a loan or invest comes down to guaranteed vs uncertain returns — not just comparing two rates. Here's the framework, the traps, and how to run your own numbers.
Read the guide →Tool guidesSimple vs Compound Interest: How to Calculate Both
Understand the difference between simple and compound interest, the formulas for each, and how compounding frequency changes your return — with worked examples. Check it with the free interest calculator.
Read the guide →Read, then check your own numbers
After the guide, use the related calculator for your own case.
Percentage Calculator
Find a percent of a number, a ratio, and a percentage change in one place — the three percentage calculations you use most, from discounts to tax to scores.
Finance/MathInterest Calculator
Calculate simple and compound interest, plus the total maturity value, from a principal, rate, and time. Useful for gauging savings or loan interest.
Date/EverydayDate Difference Calculator
See how many days, weeks, months, and years lie between two dates. Useful for countdowns, job tenure, and anniversaries.