---
title: "How to Calculate Percentages — Step-by-Step Guide with Examples"
description: "Learn to calculate percentages: percentage of a number, percentage change (increase/decrease), reverse percentage (find original price before VAT or discount). Worked examples included."
url: "https://worldcalculators.org/learning/how-to/percentages/"
canonical: "https://worldcalculators.org/learning/how-to/percentages/"
---

# How to Calculate Percentages

Learn to calculate percentages: percentage of a number, percentage change (increase/decrease), reverse percentage (find original price before VAT or discount). Worked examples included.

## Quick answer

Three key percentage formulas: (1) X% of Y = (X ÷ 100) × Y. (2) Percentage change = ((New − Old) ÷ Old) × 100. (3) Reverse percentage (find original) = Final ÷ (1 ± rate). Example: 25% of 80 = 20. A rise from $50 to $65 = 30% increase. A $119 price with 19% VAT included → original = 119 ÷ 1.19 = $100.

## Type 1: Percentage of a Number

Formula: Result = (Percentage ÷ 100) × Whole
Divide the percentage by 100. Quick trick: move the decimal point two places left. 25% → 0.25. 7.5% → 0.075. 100% → 1.0.

## Type 2: Percentage Change (Increase or Decrease)

Formula: % Change = ((New − Old) ÷ Old) × 100

## Type 3: Reverse Percentage (Find the Original)

Formula: Original = Final ÷ (1 + rate) for increases, or Final ÷ (1 − rate) for decreases.

Source: https://worldcalculators.org/learning/how-to/percentages/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.