Guides
Clear answers to the questions behind our calculators — each with worked examples, sources, and a tool to run your own numbers.
Money
How much house can I afford? How lenders size a mortgage with the 28/36 rule, what really goes into a monthly payment, and worked examples at different incomes and rates. 72-month vs 60-month car loans: what the longer term really costs Compare car loan terms side by side: monthly payment, total interest and negative-equity risk, with worked examples and a checklist before you sign. Compound interest explained, with real examples How compound interest works, why starting early matters, how compounding frequency changes returns, and the Rule of 72 — with worked examples.
Health
How to calculate a calorie deficit to lose weight safely Work out your maintenance calories, choose a safe deficit, and understand why the scale doesn’t move in a straight line — with worked examples and sources. What is a healthy body fat percentage? Body fat ranges for men and women, how the main measuring methods compare, and why body fat can tell you more than BMI alone.
Everyday
How to calculate hours worked, breaks and overtime Add up a timesheet correctly: converting minutes to decimal hours, unpaid breaks, overnight shifts and federal overtime basics, with worked examples. How to calculate percentages: 8 everyday examples Tips, discounts, sales tax, raises, test scores and more: the three percentage formulas you need, with step-by-step everyday examples and common traps.