How to Calculate Percentage Increase & Decrease (2026)
Percentage change is one of the most useful calculations in daily life. Whether you're tracking your salary hike, comparing product prices, or analyzing data trends, understanding how to calculate percentage increase and decrease is essential. This guide gives you the formula, simple steps, and real-life examples.
What is Percentage Change?
Percentage change tells you how much a value has increased or decreased relative to the original value. It is always expressed as a percentage (%) and can be positive (increase) or negative (decrease).
The Formula
If result is positive → Percentage Increase
If result is negative → Percentage Decrease
Step-by-Step Examples
Example 1 " Salary Hike:
Old salary: 40,000 | New salary: 46,000
% Increase = (46,000 40,000) 40,000 — 100 = 6,000 40,000 — 100 = 15% increase
Example 2 " Price Discount:
Original price: 2,000 | Sale price: 1,500
% Decrease = (2,000 1,500) 2,000 — 100 = 500 2,000 — 100 = 25% decrease
Example 3 " Stock Price:
Stock at 850 → drops to 750
% Decrease = (850 750) 850 — 100 = 100 850 — 100 📧 11.76% decrease
Finding Original Value from a Percentage Change
If a value increased by 20% and is now 1,200, what was the original?
Original = New (1 + %/100) = 1,200 1.20 = 1,000
Use Our Free Percentage Calculator
Calculate % Increase/Decrease Instantly " Free!
Enter the original and new value to get the percentage change instantly. No sign-up required.
Open Percentage Calculator →Also check the Percentage Formula Guide for more percentage types and use cases.
FAQs
What if the original value is 0?
Percentage change is undefined when the original value is zero, as division by zero is mathematically impossible.
Is a 100% increase the same as doubling?
Yes. A 100% increase means the value has doubled. A 200% increase means the value is now three times the original.