Guides
Practical, no-fluff guides that explain the math behind everyday decisions — age, zakat, VAT, calories, salaries and more. Every guide opens with the direct answer, then shows the working.
Calorie Deficit and TDEE: How to Calculate Your Daily Calories
To calculate your daily calories, estimate your BMR with the Mifflin-St Jeor formula, then multiply it by an…
Compound Interest Explained: Formula, Rule of 72 and Examples
Compound interest is calculated as A = P × (1 + r/n)^(nt), where P is the principal, r the annual rate as a…
Hijri vs Gregorian Calendar: Conversion Guide (2026)
The Hijri calendar is a lunar calendar of twelve months totalling about 354 days, roughly 11 days shorter…
How to Calculate Age: Years, Months and Days (2026)
To calculate age, subtract the birth date from today and count completed units: full years first, then full…
Pregnancy Weeks and Due Dates: How the Calculation Works
A due date equals the first day of your last period plus 280 days, a method called the Naegele rule.…
Hourly to Annual Salary: All the Pay Conversions Explained
Annual salary equals your hourly rate multiplied by hours per week and by 52 weeks: 25 per hour at 40 hours…
VAT Rates by Country and How to Calculate VAT (2026)
VAT is a consumption tax charged on most sales; standard rates in 2026 range from 5 percent in the UAE to 20…
How to Calculate Zakat: Step-by-Step Guide (2026)
Zakat is 2.5 percent of eligible wealth owed once your zakatable assets, minus immediate debts, stay above…