## Understanding Percentage Change Formula: Definition and Examples

Percentage change formula is one of the fundamental concepts of mathematics that helps us understand how much a value has increased or decreased over a specific period. It is an essential concept that is widely used in economics, finance, science, and other fields. In this blog post, we will discuss the percentage change formula, its applications, and examples to help you understand it better.

## Definition of Percentage Change Formula

Percentage change is a way to express the difference between two values as a percentage. It is commonly used to calculate the difference between the initial value and the final value of a particular variable. To calculate the percentage change, use the formula:

Percentage Change = ((Final Value – Initial Value) / Initial Value) x 100.

The percentage change formula is also known as the percentage difference formula. The result of the formula is expressed in percentage form. The numerator of the formula represents the difference between the final and initial values, and the denominator represents the initial value. We multiply the difference by 100 to express it as a percentage.

Find out what is 2/5 as a percentage

### Example 1: Percentage Increase

Suppose you invested $1,000 in a stock, and after a year, the value of the stock increased to $1,200. You can use the percentage change formula to calculate the percentage increase in the stock value as follows:

Percentage Change = ((Final Value – Initial Value) / Initial Value) x 100

Percentage Increase = ((1200 – 1000) / 1000) x 100

Percentage Increase = (200 / 1000) x 100

Percentage Increase = 20%

In this example, the stock value increased by 20%. The initial value was $1,000, and the final value was $1,200.

### Example 2: Percentage Decrease

Suppose the price of a laptop was $800 last year, and this year, the price of the same laptop is $640. You can use the percentage change formula to calculate the percentage decrease in the price of the laptop as follows:

Percentage Change = ((Final Value – Initial Value) / Initial Value) x 100

Percentage Decrease = ((640 – 800) / 800) x 100

Percentage Decrease = (-160 / 800) x 100

Percentage Decrease = -20%

In this example, the price of the laptop decreased by 20%. The initial value was $800, and the final value was $640.

## Applications of Percentage Change Formula

The percentage change formula has various applications in different fields. Here are a few examples:

### Economics

The percentage change formula is a vital concept in economics, and it is widely used to measure changes in economic indicators such as inflation, economic growth, and other economic variables. Here are some examples of how the percentage change formula is used in economics:

**Inflation**

The percentage change formula is used to measure the percentage increase or decrease in the price of goods and services over time. Inflation is the rate at which the general level of prices for goods and services is rising, and it is measured using various economic indicators such as the Consumer Price Index (CPI) and the Producer Price Index (PPI). The percentage change formula is used to calculate the percentage increase or decrease in the prices of goods and services over time.

For example, suppose the price of a gallon of milk was $3 last year, and this year it has increased to $3.50. The percentage increase in the price of milk can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = (($3.50 – $3) / $3) x 100%

Percentage Increase = 16.67%

Find out what is 1/6 as a percentage

**Economic Growth**

The percentage change formula is also used to measure the percentage increase or decrease in Gross Domestic Product (GDP) over time. GDP is the total value of goods and services produced within a country’s borders, and it is used as an indicator of economic growth. The percentage change formula is used to calculate the percentage increase or decrease in GDP over a specific period.

For example, suppose a country’s GDP was $100 billion last year, and this year it has increased to $110 billion. The percentage increase in GDP can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = (($110 billion – $100 billion) / $100 billion) x 100%

Percentage Increase = 10%

**Other Economic Variables**

The percentage change formula is also used to measure the percentage increase or decrease in other economic variables such as the unemployment rate, trade balance, and interest rates. By using the percentage change formula, economists can monitor changes in economic variables and make informed decisions.

For example, suppose the unemployment rate was 5% last year, and this year it has increased to 6%. The percentage increase in the unemployment rate can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = ((6% – 5%) / 5%) x 100%

Percentage Increase = 20%

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### Finance

The percentage change formula is a critical tool in finance, where it is used to measure various financial indicators such as the return on investment, stock prices, and other financial instruments. Here are a few examples of how the percentage change formula is used in finance:

**Return on Investment (ROI)**

The percentage change formula is used to calculate the ROI, which is the rate of return on an investment relative to its initial cost. ROI is calculated by dividing the net profit of an investment by its cost and multiplying the result by 100. The percentage change formula is used to calculate the percentage increase or decrease in the ROI over a specific period.

For example, suppose you invest $1,000 in a stock and sell it for $1,200 after a year. The net profit of the investment is $200, and the cost of the investment is $1,000. To calculate the ROI, you can use the percentage change formula in the following way:

ROI = (Net Profit / Cost) x 100%

ROI = ($200 / $1,000) x 100%

ROI = 20%

**Stock Prices**

The percentage change formula is used to measure the percentage increase or decrease in stock prices over a specific period. Stock prices are affected by various factors, such as company performance, industry trends, and macroeconomic conditions. By using the percentage change formula, investors can monitor the performance of their investments and make informed decisions.

For example, suppose a stock is trading at $100 per share at the beginning of the year and increases to $120 per share at the end of the year. The percentage increase in the stock price can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = (($120 – $100) / $100) x 100%

Percentage Increase = 20%

**Other Financial Instruments**

The percentage change formula is also used to measure the percentage increase or decrease in other financial instruments such as bonds, mutual funds, and exchange-traded funds (ETFs). By using the percentage change formula, investors can monitor the performance of their investments and make informed decisions.

For example, suppose an investor buys a bond with a face value of $1,000 that pays a coupon rate of 5% per year. If the bond price increases to $1,050, the percentage increase in the bond price can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = (($1,050 – $1,000) / $1,000) x 100%

Percentage Increase = 5%

### Science

The percentage change formula is a valuable tool in science that is used to measure changes in variables such as temperature, pressure, and concentration. Here are some examples of how the percentage change formula is used in science:

**Temperature**

The percentage change formula is used to calculate the percentage increase or decrease in temperature over a specific period. Temperature is a measure of the average kinetic energy of particles in a substance, and it is essential in many scientific fields such as chemistry, physics, and biology. The percentage change formula is used to measure the percentage increase or decrease in temperature over time.

For example, suppose the temperature in a laboratory was 20°C last year, and this year it has increased to 25°C. The percentage increase in temperature can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = ((25°C – 20°C) / 20°C) x 100%

Percentage Increase = 25%

**Pressure**

The percentage change formula is also used to calculate the percentage increase or decrease in pressure over a specific period. Pressure is a measure of the force per unit area, and it is essential in many scientific fields such as chemistry, physics, and engineering. The percentage change formula is used to measure the percentage increase or decrease in pressure over time.

For example, suppose the pressure in a container was 10 atm last year, and this year it has decreased to 8 atm. The percentage decrease in pressure can be calculated using the percentage change formula as follows:

Percentage Decrease = ((Old Value – New Value) / Old Value) x 100%

Percentage Decrease = ((10 atm – 8 atm) / 10 atm) x 100%

Percentage Decrease = 20%

**Concentration**

The percentage change formula is also used to calculate the percentage increase or decrease in the concentration of a substance over a specific period. Concentration is a measure of the amount of solute in a given amount of solvent, and it is essential in many scientific fields such as chemistry and biology. The percentage change formula is used to measure the percentage increase or decrease in the concentration of a substance over time.

For example, suppose the concentration of a solution was 0.1 M last year, and this year it has increased to 0.2 M. The percentage increase in the concentration of the solution can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = ((0.2 M – 0.1 M) / 0.1 M) x 100%

Percentage Increase = 100%

### Marketing

The percentage change formula is widely used in marketing to measure the change in sales, revenue, and market share. It is used to calculate the percentage increase or decrease in these variables over a specific period. Here are some examples of how the percentage change formula is used in marketing:

**Sales**

The percentage change formula is used to calculate the percentage increase or decrease in sales over a specific period. Sales are one of the most critical variables in marketing, and the percentage change formula is used to measure the percentage increase or decrease in sales over time.

For example, suppose a company had $1 million in sales last year, and this year it has increased to $1.5 million. The percentage increase in sales can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = ((1.5 million – 1 million) / 1 million) x 100%

Percentage Increase = 50%

**Revenue**

The percentage change formula is also used to calculate the percentage increase or decrease in revenue over a specific period. Revenue is a measure of the income generated by a business, and it is an essential variable in marketing. The percentage change formula is used to measure the percentage increase or decrease in revenue over time.

For example, suppose a company had $5 million in revenue last year, and this year it has decreased to $4 million. The percentage decrease in revenue can be calculated using the percentage change formula as follows:

Percentage Decrease = ((Old Value – New Value) / Old Value) x 100%

Percentage Decrease = ((5 million – 4 million) / 5 million) x 100%

Percentage Decrease = 20%

**Market Share**

The percentage change formula is also used to calculate the percentage increase or decrease in market share over a specific period. Market share is a measure of the company’s sales or revenue compared to the total market sales or revenue, and it is a critical variable in marketing. The percentage change formula is used to measure the percentage increase or decrease in market share over time.

For example, suppose a company had a market share of 10% last year, and this year it has increased to 15%. The percentage increase in market share can be calculated using the percentage change formula as follows:

Percentage Increase = ((New Value – Old Value) / Old Value) x 100%

Percentage Increase = ((15% – 10%) / 10%) x 100%

Percentage Increase = 50%

## Limitations of Percentage Change Formula

Although the percentage change formula is an essential concept, it has some limitations that you should keep in mind. One of the limitations is that it does not consider the absolute value of the change. For instance, a 20% increase in a $10 item results in a change of only $2, whereas a 20% increase in a $1,000 item results in a change of $200. Therefore, it is essential to consider the actual amount of change in addition to the percentage change.

Another limitation of the percentage change formula is that it only considers the initial and final values, without accounting for any intermediate changes that might have occurred during the period. For example, if the stock price increased by 10% in the first month and then decreased by 5% in the second month, the percentage change formula would not reflect these intermediate changes.

In addition, the percentage change formula assumes that the initial value is the baseline, which might not always be the case. For example, in the case of a temperature change, the baseline might be the average temperature for the month, rather than the initial temperature.

Find out what is 1/3 as a percentage

## Summary

The percentage change formula is a powerful tool that helps us understand how much a value has increased or decreased over a specific period. It is widely used in various fields, such as economics, finance, science, and marketing. However, it is essential to keep in mind its limitations and consider the absolute amount of change in addition to the percentage change. Additionally, the formula assumes that the initial value is the baseline, which might not always be the case.

In summary, the percentage change formula is a useful concept that can provide valuable insights into various phenomena. By understanding the formula and its applications, you can gain a better understanding of how changes occur and how they can be measured.