How to Calculate Percentage Decrease (With Examples)

Percentage decrease helps you measure how much a value has dropped relative to its original amount. Whether you're tracking price cuts, reduced expenses, or lower performance metrics, it's a handy tool for understanding reductions clearly.

Percentage Decrease = ((Original Value - New Value) / Original Value) × 100

Example 1: Basic Percentage Decrease

If a product's price drops from $100 to $80, what is the percentage decrease?

  Decrease = 100 - 80 = 20
  Percentage Decrease = (20 / 100) × 100 = 20%
  

Example 2: Usage Decrease

Your monthly data usage went from 10GB to 7.5GB. What's the percentage drop?

  Decrease = 10 - 7.5 = 2.5
  Percentage Decrease = (2.5 / 10) × 100 = 25%
  

Real-Life Applications

• Retail: Understand discount percentages on sales items.
• Finance: Track drops in stock prices or income.
• Environment: Measure reductions in emissions or energy use.
• Health: Calculate weight loss as a percentage.

Practice Questions

1. A product price drops from $150 to $120. What's the percentage decrease?
2. Website traffic falls from 2,000 to 1,600 visits. What is the decrease in percentage?
3. A population declines from 10,000 to 9,000. What's the percent drop?

Answers:

• 20%
• 20%
• 10%

Summary

Percentage decrease is essential for evaluating reductions over time. It's calculated by dividing the amount of decrease by the original value, then multiplying by 100.

Percentage Decrease = ((Original - New) / Original) × 100

From business analytics to daily budgeting, this formula gives you clear insights into declining values.