Today we will learn how to calculate weighted average in Excel with percentages.
What is weighted average ?
Weighted average or weighted mean is defined as [from wikipedia],
The weighted mean is similar to an arithmetic mean …, where instead of each of the data points contributing equally to the final average, some data points contribute more than others.
…If all the weights are equal, then the weighted mean is the same as the arithmetic mean.
Why should you calculate weighted average?
Well, it is because, in some situations normal averages give in-correct picture. For eg. assume you are the CEO of ACME Widgets co.. Now you are looking annual salary report and being the numbers-gal you are, you wanted to find-out the average salary of your employees. You asked each department head to give you the average salary of that department to you. Here are the numbers,
Now, the average salary seems to be $ 330,000 [total all of all salaries by 5, (55000+65000+75000+120000+1200000)/5 ].
You are a happy boss to find that your employees are making $330k per year.
Except, you are wrong. You have not considered the number of employees in each department before calculating the average. So, the correct average would be $76k as shown above.
How to Calculate Weighted Average in Excel with Percentages
There is no built-in formula in Excel to calculate weighted averages. However, there is an easy fix to that. You can use SUMPRODUCT formula. By definition, SUMPRODUCT formula takes 2 or more lists of numbers and returns the sum of product of corresponding values. [related: Excel SUMPRODUCT Formula – what is it and how to use it?]
So, if you have values in B4:B8 and the corresponding weights in C4:C8, you can use SUMPRODUCT like this to get weighted average.
=SUMPRODUCT(B4:B8, C4:C8)
Caution: However, the above method works only if C4:C8 contains weights in percentages(%) totaling to 100%.
WAvg Formula Pattern (use this with your data)
=SUMPRODUCT(<your values>, <your weights>)What if my percentage weights don’t add up to 100%?
May be your weights are more than 100 percent. Or may be they are less than 100 percent. In both cases, you can use the below formula variation.
=SUMPRODUCT(B15:B19, C15:C19) / SUM(C15:C19)
The idea is to divide the total of weights with the SUMPRODUCT result so that we can adjust Weighted Average as the weights don’t add up to 100 percent.
WAvg Formula Pattern when weights don’t add up to 100 percent
=SUMPRODUCT(<your values>, <your weights>) / SUM(<your weights>)Weighted Average when you have counts instead of weights:
If you have count of observations instead of weights, you can still use the SUMPRODUCT formula to calculate weighted average in Excel.
Here is the formula for above example:
=SUMPRODUCT(B26:B30, C26:C30) / SUM(C26:C30)
Notice that this formula is same as the formula for weighted average with weights not adding up to 100 percent.
WAvg Formula Pattern when you have counts instead of weights
=SUMPRODUCT(<your values>, <your counts>) / SUM(<your counts>)Weighted Average with Extra Conditions
Let’s say you have city wise observations and weights. And you want to calculate the weighted average, only for Boston values. In this case, you can use a variation of the formula like below:
=SUMPRODUCT((C5:C16)*(B5:B16=F5),D5:D16)/SUMIFS(D5:D16,B5:B16,F5)
How does this formula work?
- SUMPRODUCT calculates the total value for BOSTON by summing up C5:C16 (value column) where B5:B16 is Boston (highlighted portion of the formula) and multiplies that with the counts.
- So in the above example, this will just give us the total of Boston – ie 218,600
- We then divide this with the total count of Boston (using the SUMIFS formula) – ie 400
- This results in the weighted average for Boston values alone – ie 546.50
For more information on how the conditions work inside SUMPRODUCT formula, please read this article.
Download Weighted Average Calculation Example Workbook:
In this workbook, you can find 4 examples on how to to calculate weighted average in excel. Go ahead and download it to understand the formulas better.
Weighted Average in Excel – Formula Explained
Here is a video with Weighted Average formula explained. Please watch it below to learn more. Alternatively, head to my YouTube page to see the weighted averages in Excel video.
In Conclusion
Weighted averages are a great way to explain data and every data analyst should know how and when to use them with their data. Apart from Weighted Average, I suggest learning how to use moving average and average of top n values. These will help you explain the data and trends to your audience better.
Do you use Weighted Mean / Weighted Average?
What do you use it for? What kind of challenges you face? Do you apply any tweaks to weighted average calculations? Please share your ideas / tips using comments.
19 Responses to “Free Invoice Template using Excel – Download”
Nice post! Invoicing for the small biz or solo entrepreneur is something I see a lot of interest in. Also there are great templates from http://office.microsoft.com/en-us/templates
This is awesome.
I would need a little more. e.g. say I generate a Inv. # 1 with all the details. Once done I can click a button all the relevant details gets stored in some table. Further, when i generate a new invoice those details gets stored in same table but just below the previous invoice.
Is their a way to do this?
I did create a solution you are looking for, however its wrapped in a larger 'Medical Scheduler' and it uses VBA, But you can Save, Update, Lookup, Email, Print & Apply Payments to the Invoice.
You are welcome to download it here:https://www.dropbox.com/s/2yvo0o2tgq9quhe/Medical_Massage_and_Salon_Application-Free.xlsm
The Invoice Items are created from the Appt. Types & Service Items table.
I would love all feedback from this
Thank you for sharing. I will definitely have a look at it.
Daily dose of Excel held a competition in 2005 for this same topic
It obtained 9 solutions which are shown:
http://dailydoseofexcel.com/archives/2005/10/27/invoice-app-the-results/
[…] http://chandoo.org/wp/2014/03/19/free-invoice-template/?utm_source=feedburner&utm_medium=email&a… […]
How can i removed Dollar Sign, As want to use this in india.
Please reply.
Also if possible then can i use Indian Rupee Sign and how?
Hi Chandoo,
Thanks for sharing this invoice template, Let me tell you this template will definitely help me since I got a process to handle where this invoice piece comes. Just a small doubt, can we store all the invoice details in PRODUCT & SERVICES sheet. So that whenever I select an invoice number from invoice sheet I can take print out and I can share it as well. Can we do that?? Since I will be dealing with this on monthly basis.
It would be great if you can help me with this.
Thanks in advance for your help!
Regards,
Gaurang Mhatre
Hi Chandoo,
I was thinking learning excel is quite tuff task but your blog proved me wrong. You made it very interesting. Thank you. Also the template you have provided for Invoice is very helpful to us.
Thanks thanks thanks.. Very helpful. 🙂
Hi i love the speadsheet but would like to ask how do i get it to add the description into the invoice as well
Hi Randy, I tried to download one of your link "https://www.dropbox.com/s/2yvo0o2tgq9quhe/Medical_Massage_and_Salon_Application-Free.xlsm" However, i found the link unavailable. Can you please help me get the new link or can you please send this VBA file on my Email-ID.
Hello Anuj,
Thanks for alerting me to the broken link. This one should work:
https://www.dropbox.com/s/gz89gshex1ad0ex/Medical_Massage_and_Salon_Application-Free.xlsm?dl=0
Please let me know if you have any questions.
Randy
Thank you so much Buddy. will check and revert you soon.
Hi, is there any chance that this can work with the "Products & Service" sheet outside of the Invoice sheet. I create multiple invoice files for the numerous clients. Updating the product sheet for each of them maybe a task. Hence, I want to create a MASTER FILE from which data can be picked up without having to insert new data in each of the invoice files.
Possible? Or am I asking for the moon 😉
Thank you so much for tutorial.
This example can be reviewed for the example of the advanced invoice that made with excel userform :https://youtu.be/Qr-4of-38DI
Good Day
i love this template may i ask if it could be modified to have the following
when you lookup a item code in the next column to the right it brings up the description then the quantity, unit cost, discount and then total otherwise i love the template
Item Code Description Quantity Unit Cost Discount Total
When creating an Invoice template in Excel are you able to utilize the auto row height and wrap feature when the cell is a merged cell? I need to have a number of cells merged together to allow for enough space to type in the description of work performed (lets say cells A-D are merged in each row) however it seems that I am unable to utilize the auto format feature. To work around this I have to manually increase the row height after each entry. Is there a better solution for this? Thank you!