WorldlyCalc Blog — Guides, Tips & How-Tos for Everyday Calculations

How Much House Can I Afford?

Learn the 28/36 rule, understand debt-to-income ratios, and figure out a realistic home-buying budget before you start shopping.

Understand Body Mass Index: the formula, WHO categories, its limitations, and better alternatives for measuring body composition.

Master percentage calculations with step-by-step examples: percentage of a number, percentage increase/decrease, and percentage difference.

Learn how compound interest works, why Einstein reportedly called it the eighth wonder, and how compounding frequency affects your returns.

Calculate your Body Mass Index by hand in both metric and imperial units. Includes worked examples and a quick-reference category chart.

Break down the mortgage payment formula, understand PITI, and see a worked example with a $300K home at 6.5% over 30 years.

Learn how TDEE works, the difference between BMR and TDEE, activity multipliers, and how to use it for weight loss or muscle gain.

Understand the 4% rule, age-based savings benchmarks, 401(k) vs IRA comparison, and how starting early changes everything.

Understand zakat's role in Islam, the nisab threshold, which assets are zakatable, and how to calculate your annual obligation.

Master GPA calculation on the 4.0 scale with grade conversion tables, worked examples, and the difference between weighted and unweighted GPA.

Color-coded BMI chart for quick lookups by height and weight. Available in both imperial and metric units.

Complete 2026 federal income tax brackets for all filing statuses, with standard deductions and example calculations.

Sortable table of median home prices, average mortgage rates, and estimated monthly payments across all 50 US states.