How do I calculate percentage change?

Formula: Percentage Change = ((New Value - Old Value) / |Old Value|) × 100. Positive result = increase, negative = decrease. For example, from 50 to 75: (75-50)/50 × 100 = 50% increase.

What's the difference between percentage change and percentage point change?

Percentage change is relative to the starting value (50 to 75 = 50% increase). Percentage point change is absolute difference (interest rate from 5% to 8% = 3 percentage points, but 60% relative increase).

Can percentage change be negative?

Yes. Negative percentage change indicates a decrease. For example, from 100 to 80 = -20% change (20% decrease).

How do I calculate reverse percentage change?

To find original value from percentage change: Original = New Value / (1 + Percentage Change/100). For example, if $120 is after 20% increase: 120 / 1.20 = $100 original.

What are common uses of percentage change?

Finance: stock price changes, sales growth. Economics: inflation, GDP growth. Business: revenue changes, market share. Science: experimental results. Retail: price markdowns, discounts.

Percentage Change Calculator - Find Increase/Decrease Percentage

Percentage Change Calculator

Calculate percentage increase or decrease between two values. Perfect for analyzing price changes, salary adjustments, business growth, and more.

100% FreeStep-by-step SolutionsReal-world Examples

Calculator

Choose calculation type and enter your values to find the percentage change

Enter to calculate, Esc to clear

Starting Value *

Original or initial value

Final Value *

New or ending value

Real-Life Examples

Click on any example to automatically fill the calculator

Shopping

Product price dropped from $50 to $40

Result: 20.0% decrease

Salary

Monthly salary increased from $3,000 to $3,300

Result: 10.0% increase

Stock

Stock price fell from $100 to $85

Result: 15.0% decrease

Sales

Company revenue grew from $1M to $1.2M

Result: 20.0% increase

The Percentage Change Formula

\\text{Change Rate} = \\frac{\\text{New Value} - \\text{Old Value}}{\\text{Old Value}} \\times 100\\%

or in English:

\\text{Change Rate} = \\frac{\\text{New Value} - \\text{Old Value}}{\\text{Old Value}} \\times 100\\%

This formula is your go-to tool for comparing any two numbers in context. Whether you're tracking stock prices, analyzing sales data, or just comparing grocery prices from last month, percentage change gives you a standardized way to measure growth or decline.

Stock Market

Tesla Stock Drop

Price fell from $120 to $90

Calculation:

\\frac{90 - 120}{120} \\times 100

= $\\frac{-30}{120} \\times 100$

= -25% (25% decrease)

Salary Raise

Annual Review Bonus

Monthly pay: $5,000 → $5,750

Calculation:

\\frac{5750 - 5000}{5000} \\times 100

= $\\frac{750}{5000} \\times 100$

= 15% (pay raise!)

Black Friday Deal

Laptop Sale

Price: $299 → $199

How good is this deal?

\\frac{199 - 299}{299} \\times 100

= $\\frac{-100}{299} \\times 100$

≈ -33.4% (1/3 off!)

Easy-to-Confuse Concepts (Pay Attention!)

Percentage Change ≠ Percentage Points

📊 Percentage Change

Interest rate: 5% → 8%

\\frac{8-5}{5} \\times 100 = 60\\% \\text{ increase}

(Relative to the original 5%)

📍 Percentage Points

Interest rate: 5% → 8%

8 - 5 = 3 percentage points

(Absolute difference)

News headlines often mix these up! "Inflation rose 2 percentage points" means from 3% to 5%. "Inflation rose by 2%" means from 3% to 3.06%.

Why +50% and -50% Don't Cancel Out

Here's something that trips people up: if your stock goes up 50% then down 50%, you don't end up where you started!

Example: $100 investment

Step 1: +50% → $100 × 1.5 = $150

Step 2: -50% → $150 × 0.5 = $75

Result: You lost $25 (25% total loss)

💡 This is because percentage changes are multiplicative, not additive. The second percentage operates on an already-changed base value.

Real-World Applications

Investment Analysis

Track your portfolio performance, compare mutual funds, or calculate ROI on property investments. Essential for making data-driven financial decisions.

Business Metrics

Month-over-month revenue growth, customer acquisition rates, conversion rate improvements. Every business dashboard uses percentage change.

Price Monitoring

Amazon price trackers, gas price trends, real estate market analysis. Know when you're getting a genuine deal vs. fake "discounts."

Data Science & ML

Feature engineering for machine learning models. Normalizing time-series data. Calculating model performance improvements.

Frequently Asked Questions

Percentage Change = ((New Value - Old Value) / Old Value) × 100. A positive result indicates increase, negative indicates decrease. Example: From 50 to 75 is ((75-50)/50)×100 = 50% increase.

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