Percentage Calculator

Calculate the difference of a percentage when increasing or decreasing any number by percentages. The percentage change calculator can be used to figure out taxes, for school, or in any situation where you need to determine the percentage of something—whether you want to increase or decrease a number.

How to Use the Percentage Calculator

Using the Percentage Calculator on our site is very easy. Follow these steps to calculate the percentage increase or decrease of any number:

1. Enter the original number:
   Start by typing the number you want to adjust in the “Original Number” field. For example, if you want to calculate a percentage change for 100, enter “100.”
2. Enter the percentage:
   In the “Percentage (%)” field, enter the percentage value you want to increase or decrease. For example, if you’re calculating a 20% increase, enter “20.”
3. Select the change type:
   Use the dropdown menu to choose whether you want to “Increase” or “Decrease” the original number by the percentage you entered.
4. Click the “Calculate” button:
   Once you’ve filled out all the fields, click the “Calculate” button. The calculator will instantly show you the results.
5. View your results:
   The results will display the following:
   • The original number you entered.
   • The percentage and type of change (increase or decrease).
   • The amount of change calculated.
   • The final number after applying the percentage adjustment.

This calculator is perfect for a variety of situations, like calculating discounts, tax adjustments, or even figuring out changes in measurements or statistics. Use the percentage difference calculator on our website to get your answers quick.

Why I Created the Percentage Difference Calculator

Many years ago, back in my younger days, I struggled with math—especially when it came to percentages. I could figure out some basic percentages in my head, but calculating percentage increases or decreases on paper always left me scratching my head. I remember constantly searching for YouTube videos to explain how to increase or decrease percentages. It was frustrating, and I always thought, “Why isn’t there a simpler way?”

These days, we all have calculators on our phones, but let’s be honest—sometimes they’re buried in menus, and it’s just faster and easier to Google or Bing the answer. That’s why I wanted to create a this calculator that’s simple, quick, and accessible to anyone, no matter their math skills.

Personally, one of the biggest reasons I use percentage calculations is for my paycheck. Like most people, I love getting paid every few weeks, and I always want to know what I’ll actually be taking home after taxes. I’ve gotten into the habit of estimating a 30% decrease from my gross pay to figure out my net paycheck. This helps me plan with my wife—we sit down and decide how much we’ll save, what we’ll spend, and where we can make adjustments.

Frequently Asked Questions

1. How do I calculate a percentage increase?

To calculate a percentage increase, you need to determine how much a number has grown in relation to the original number. For example, if your paycheck increased from $2,000 to $2,200:

• Subtract the original amount from the new amount: $2,200 – $2,000 = $200
• Divide the increase by the original number: $200 ÷ $2,000 = 0.1
• Multiply by 100 to get the percentage: 0.1 × 100 = 10%
  Your paycheck increased by 10%.

2. How do I calculate a percentage decrease?

To calculate a percentage decrease, follow the same process but account for the drop. For example, if your grocery bill decreased from $300 to $240:

• Subtract the new amount from the original amount: $300 – $240 = $60
• Divide the decrease by the original number: $60 ÷ $300 = 0.2
• Multiply by 100 to get the percentage: 0.2 × 100 = 20%
  Your grocery bill decreased by 20%. (unfortunately our grocery bills keep increasing every year)

3. How do I calculate percentages on paper?

If you don’t have a calculator, calculating percentages on paper is straightforward. Let’s say you want to find 15% of $80:

• Write down the percentage as a fraction or decimal: 15% = 0.15
• Multiply it by the number: $80 × 0.15 = $12
  15% of $80 is $12.

For increases or decreases:

• Multiply the original number by the percentage (in decimal form).
• Add or subtract the result from the original number, depending on whether you’re increasing or decreasing.

Example for a 20% increase on $50:

• $50 × 0.20 = $10
• $50 + $10 = $60
  The new number is $60.

4. How do I calculate percentages without a calculator?

If you don’t have a calculator, you can estimate percentages in your head. Here’s how:

• 10% of a number: Move the decimal one place to the left. For $50, 10% is $5.
• 5% of a number: Take half of 10%. For $50, 5% is $2.50.
• 1% of a number: Move the decimal two places to the left. For $50, 1% is $0.50.

Example: To find 15% of $50:

• Find 10%: $5
• Find 5%: $2.50
• Add them together: $5 + $2.50 = $7.50
  15% of $50 is $7.50.

5. How do I calculate percentage difference between two numbers?

Let’s say you want to compare test scores—one person scored 80, and another scored 100:

• Subtract the smaller number from the larger: 100 – 80 = 20
• Divide the difference by the original number: 20 ÷ 80 = 0.25
• Multiply by 100 to get the percentage: 0.25 × 100 = 25%
  The difference is 25%.

6. How do I calculate percentage change in Excel?

You can use the formula =(New Value - Old Value)/Old Value * 100 in a cell. For example, if cell A1 has the old value ($100) and cell B1 has the new value ($150), the formula in cell C1 would be:
=(B1-A1)/A1*100
This will give you a 50% increase.

7. How do I calculate percentage reduction?

If a $50 product is on sale for $40:

• Subtract the sale price from the original price: $50 – $40 = $10
• Divide the difference by the original price: $10 ÷ $50 = 0.2
• Multiply by 100 to get the percentage: 0.2 × 100 = 20%
  You’re getting a 20% discount.

8. How do I calculate two percentages together?

If you’re applying two discounts—say 20% and then 10%—to a $100 item:

• First, calculate the 20% discount: $100 × 0.2 = $20
• Subtract the first discount: $100 – $20 = $80
• Then, calculate the 10% discount on the new price: $80 × 0.1 = $8
• Subtract the second discount: $80 – $8 = $72
  The final price after both discounts is $72.

9. How do I calculate a percentage of something?

If you ate 3 slices of an 8-slice pizza:

• Divide the part by the whole: 3 ÷ 8 = 0.375
• Multiply by 100: 0.375 × 100 = 37.5%
  You ate 37.5% of the pizza.

10. How do I calculate gross profit percentage?

Let’s say your business revenue is $5,000, and your costs are $3,000:

• Subtract costs from revenue: $5,000 – $3,000 = $2,000
• Divide the profit by the revenue: $2,000 ÷ $5,000 = 0.4
• Multiply by 100: 0.4 × 100 = 40%
  Your gross profit percentage is 40%.

Final Thoughts

Percentages are one of those things we all deal with, whether it’s figuring out discounts, budgeting paychecks, or comparing numbers. But let’s be honest, doing the math in your head or even on paper can get tricky sometimes. That’s exactly why I created this percentage calculator—to make your life easier.

With this tool, you don’t have to waste time Googling formulas or fumbling with numbers. Just plug in what you know, hit calculate, and you’ve got your answer in seconds. Add this calculator to your bookmarks or home page so you can get easy access.