Percentage Math: Calculate Discounts & Tax Like a Pro

Master the simple formulas that power your daily financial decisions.

May 12, 2026 • Roshan Karki • 5 min read

Percentages are everywhere—from the 20% tip at a restaurant to the 15% VAT on your utility bill. Despite their prevalence, many people find percentage math intimidating. We break it down into simple, repeatable formulas that you can use anywhere.

The Core 3 Formulas

  • 1. Finding the Percentage:
    (Part / Whole) x 100
  • 2. Calculating a Discount:
    Original Price x (Discount % / 100)
  • 3. Calculating a Markup (Tax):
    Original Price x (1 + (Markup % / 100))

Practical Examples

Imagine you see a jacket for $80 with a 25% discount. To find the savings, you calculate 80 x 0.25 = $20. Your final price is $60. Understanding this simple multiplication allows you to shop smarter and avoid "fake" sales.

Short on time? Use our Free Percentage Tool for instant, professional results.

RK
Roshan Karki

Computer Engineering graduate from Tribhuvan University with over 5 years of experience in browser-side utility engineering, who has built 15+ standalone browser tools serving thousands of users globally.