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Percentage Increase and Decrease Calculator

QUICK LINKS

STUDENT
TEACHER

Percentage Increase and Decrease Calculator

Percentage Increase and Decrease

CALCULATOR
—

Percentage Increase and Percentage Decrease Calculator

What are you solving for?
What isby?

Step 1. Convert the percentage change to a decimal.

The percentage change as decimal represents the change relative to the initial value.
Remove the percentage sign and move the decimal places to the left.
⤻⤻

Step 2. Determine whether to add or subtract the change to/from 1.

Since we’re increasing, we add.

Step 3. Set up the equation.

The final value equals the change from multiplied by the initial value:

Step 4. Solve for the unknown.

So, our answer is
.
We have some questions for you! Help us out through this
INTRO
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To help us understand percentage increase and decrease, think about the last time you watched your phone's last 1% of battery drain away…

We know, it’s the worst. Now, imagine how great it would be if you could just increase your max battery by ? 🤩
Increasing by is like adding in of the old battery to get a much better new battery.
So now we have blocks of battery. And since a full block is worth hours, the new amount of battery time we have is hours.

This calculation actually uses the following percentage change formula:

And if, instead, we wanted to represent a percentage decrease, we would subtract the percentage change (in decimal format) from instead of adding it.

Try it out yourself!

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So there are two different percentage change equations? 🤯

Ehh, sort of. The percentage change formula above comes from a formula we may be more familiar with:

Divide both sides by to convert the percentage change into a decimal:
Multiply both sides by the initial value:
Add the initial value to both sides:
Factor out the initial value:
Rearrange a little, and voila! We have a new simplified percentage increase and percentage decrease formula:
Check out our
Calculator
or explore our
Lesson
and
Practice
sections to learn more about how to calculate initial and final values with percentage increase and decrease.

You can also use the Quick Links menu on the left to jump to a section of your choice.

You can also use the Quick Links dropdown above to jump to a section of your choice.

KEY STEPS
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How to Find the Initial and Final Value of a Percentage Increase or Decrease

Step 1. Convert the percentage change to a decimal.

The percentage change as decimal represents the change relative to the initial value.
Remove the percentage sign and move the decimal places to the left.

Step 2. Determine whether to add or subtract the change to/from 1.

  • If we’re decreasing, we subtract.
  • If we’re increasing, we add.

Step 3. Set up the equation.

The final value equals the result from Step 2 multiplied by the initial value:

or

Step 4. Solve for the unknown.

LESSON
— Calculating Final Value of Percentage Increase and Decrease
PRACTICE
— Calculating Final Value of Percentage Increase and Decrease
LESSON
— Calculating Initial Value of Percentage Increase and Decrease
PRACTICE
— Calculating Initial Value of Percentage Increase and Decrease
CONCLUSION
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