Find the Percentage Difference between numbers in Excel
Calculating percentages was my favorite topic from 5th grade Mathematics – and is to date.
It just makes the process of looking at things much simpler. Defining numbers as a percentage, you can compare any two items. No matter how different they are.
To take comparison a step ahead, we see the percentage difference between the two numbers.
This guide is all about calculating percentages and percentage differences in Microsoft Excel. I am going to tweak percentages in every way possible in the guide below 😃
So download our practice workbook for this guide here and come along with me.
What is percentage
Okay. First thing first – what is a percentage even?
I am going to quickly rewind you to elementary math 👨🏫
Percentage is a way to express a number as a proportion of 100.
For example, a student scored 40 marks out of 75 in his annual exam. What percent marks did he score?
To calculate that, first, we will see what proportion is 40 of 75.
And then, to see it as a proportion of 100, we will simply multiply it by 100.
Comes out as 53.33%. That’s how we say, a student only scored 53.33% marks.
Percentages make it easy to read data. For example, 53.3% makes it clear that the student only scored nearly half of the total marks on the test.
Kasper Langmann, co-founder of SpreadsheetoHow to calculate percentages in Excel
Excel doesn’t offer any function to calculate percentages in Excel. But you can do it quickly through the following steps.
We again have some students are their obtained marks in Chemistry. Let’s find out the percentage marks scored by each of them.
Step 1) To calculate the percentage for these marks, write the following formula:
Step 2) Press enter and drag and drop the same to the whole list.
We have got the answers in decimal. To convert these into percentages:
Step 3) Select the cells containing decimal values.
Step 4) Go to the Home Tab > Number Group > Percentage Icon.
Decimals changed from number format to percentages.
That’s how you do percentages in Excel.
What is the percent change
Percent change is the proportional difference between two numbers.
It tells how much the two values differ in terms of percentage 📈
For example, you go to a shop and buy a can of juice for $10. 2 weeks later, you walk into the mall and see the same can be retailed for $16 (that’s an insane jump by the way).
The price has increased from $10 to $16. But how much percent change is that?
It’s a 60% jump. How do you calculate that comes in the next section but, that’s what we call percent change.
The price of a juice can has changed by 60% (increased).
How to calculate the percentage change between numbers
Calculating percentage change between numbers takes two formulas.
Here’s the classic one (we will call it Formula A):
This formula divides the change in value by the old value to see the change as a proportion of the old value.
The other one is (Formula B as we say):
This formula sees what proportion the new value of the old value is and then subtracts 1 from it to reach the amount of change only.
Let’s now use these formulas to see how can you calculate percent change in Excel 👇
Increase
Calculating percent increase, huh? What’s a better example than inflation?
Here’s the list of goods and their prices as of 01 Jan 2023 and 01 Jan 2024.
The numbers seem slightly changed only. Let’s calculate and see how the percentage increase in these prices has been seen over the year.
For this example, I am using Formula B explained above.
Kasper Langmann, co-founder of SpreadsheetoStep 1) Begin writing the following formula in a new column:
We divided the new price by the old price to see the new price is 1.05 times the old price.
Step 2) Now deducting 1 from it will give us the percentage of change in the price.
Step 3) Drag and drop the same to the whole column.
Step 4) Apply the percentage formatting to this column by going to the Home Tab > Number Group > Percentage Icon.
There you go! We get the percentage change for all the prices.
Most of the prices increase by only 5%, and the maximum increase is 6.7%.
Just to double-check, the results would have been the same even if we used Formula A. See below 👀
Decrease
It’s time we see an example of calculating a percentage decrease in Excel.
Below is a set of regions and their temperature changes over the year. Scanning through the numbers shows that the temperature has fallen over the last 10 years.
Let us see the percentage change in these temperatures over the year. This time I will use Formula A to calculate the percentage decrease.
Step 1) Begin writing the following formula in a new column:
Find out the difference between the temperature now and that 10 years ago. You’d see the answers come with a negative sign 📆
Step 2) Now divide it over the old temperature (10 years ago) to see the change as a proportion of the older temperatures.
Step 3) The formula is all sorted. Just drag and drop it to the whole column.
Step 4) Apply the percentage formatting to this column by going to the Home Tab > Number Group > Percentage Icon.
This time the percentage change comes with a negative sign to denote that the temperatures have dropped over time.
That’s how we calculate percentage decreases in Excel.
Absolute
We’ve seen how to calculate percentage increases and decreases in Excel. And for decrease, the percentage difference comes with a minus sign to show that the numbers have decreased.
However, there might be instances where you’d only want to calculate the percent change. Without the distinction between increase or decrease (i.e., no signs with the percent change).
For this, you need to use the ABS function. Let me show you here.
I have tweaked some numbers from our above example to show regions where temperature has increased over the period, too 🥶
To yield the percentage difference from these numbers as an absolute value:
Step 1) Write the formula for calculating the percentage difference as follows:
This formula gives you the percentage difference.
Step 2) Now wrap the above formula into the ABS function as below.
Here’s with the percentage format applied.
We still have the percentage difference calculated but this time it is in absolute terms (positive value).
The temperature of Minnesota changed by 367% over the years (increased or decreased we don’t know).
How to apply percentage increase/decrease to numbers
This section is going to be the reverse working of what we did above.
How do you apply a certain percentage of increase or decrease to numbers? I will show you how.
Strolling through malls you’d have seen those big banners of 20% discount (or any percentage). Discount means the price will be decreased by that % 🥼
Come let’s apply it to see how you calculate that in Excel.
Each item has a different price and a certain discount percentage. To find the after-discount prices:
Step 1) Write the following formula.
Deducting the discount percentage from 1 gives us the net price.
The T-shirt bears a 20% discount (20% less price) so you’re technically paying only the 80% price. Deducting 20% (which denotes 0.2) from 1 gives us 80% (or 0.8).
In the above formula, we are multiplying the price of the T-shirt by the after-discount rate of 80% (1-20%).
The T-shirt retails for $18 after a discount. And here’s the after-discount price list for all other items.
That’s how you apply a percentage decrease to a number. And what about the percentage increase?
Only if this was not a 20% discount but a 20% rate increase, we would have tweaked the formula above as follows:
Just the minus sign is substituted by a plus sign (since the prices are increasing this time).
With a 20% increase, the price of the T-shirt becomes $22 💸
Find the total from percentages in Excel
If you are a person of numbers, you’ll love this section.
We are just doing some reverse work again. So, let’s say you know a shirt is selling at a 35% discount for $18. Cool – just go and buy it.
But wait! What is its actual undiscounted price?
To find that:
Step 1) Put together the following formula in MS Excel
This calculates what the discounted price represents.
The discounted price of $20 represents 65% of the actual price, right? (Actual price – 35% discount).
Step 2) Divide the discounted price by what it represents (i.e., 65%)
Find us the actual price – $30.8.
Conclusion
The above tutorial has basic concepts that are often misunderstood. Practicing the above examples will help you learn smart techniques to quickly work out percentages (and work them back too).
Since percentages help you identify a pattern of increase/decrease, you can make out trend lines and spark lines in Excel to visualize these trends. Here are some other advanced Excel tutorials of mine that will help you build a better foundation of percentages/trends and related concepts.
Don’t stop here. Continue reading and learning.
Written by Kasper Langmann
My name is Kasper Langmann, and I’m the co-founder of Spreadsheeto and a certified Microsoft Office Specialist.
This tutorial reflects over 19 hours of dedicated research and writing, based on my 10+ years of professional Microsoft Excel experience.
Last updated on March 16th, 2024.
One last thing before you go: make sure to sign up for my free Microsoft Excel course!