Plain-English walkthroughs · Worked examples · Formulas shown
Guides — the math and the method behind every tool.
Short, practical reads that explain how each calculator works and how to use it well. US-oriented, jargon-free, and written to help you check the numbers yourself.
All guides
6 articles
How to Calculate Your Monthly Mortgage Payment
The amortization formula explained in plain English, with worked US dollar examples.
Finance · 8 min read
How Much House Can You Afford?
The 28/36 rule, down payments and the true monthly cost of owning a home.
Finance · 7 min read
How Compound Interest Grows Your Money
Why time beats rate, the compound formula, and the snowball shown in dollars.
Finance · 7 min read
What Is a Healthy BMI for Your Height?
The standard categories, a height table, and the real limits of BMI. General info only.
Health · 6 min read
How to Write Better AI Prompts
A five-part structure for sharper results, with before-and-after examples for text and images.
AI · 7 min read
Profit Margin vs Markup
Same profit, different math — and the pricing mistake that quietly erodes profit.
Business · 6 min read