Today, lets learn OFFSET formula.
What is OFFSET and why bother using it?
OFFSET formula gives us reference to a range, from a given starting point with given height and width in cells.
OFFSET formula syntax
OFFSET formula looks like this:
=OFFSET(starting point, rows to move, columns to move, height, width)
- Starting point: This is a cell or range from which you want to offset
- Rows & columns to move: How many rows & columns you want to move the starting point. Both of these can be positive, negative or zero. More on this below.
- Height & width: This is the size of range you want to return. For ex. 4,3 would give you a range with 4 cells tall & 3 cells wide.
And yes, All the arguments to OFFSET can be references to other cells. That means, you can write =OFFSET(A1,D1,D2,D3,D4) which will refer to a range
- Starting from A1
- Offset by D1 rows & D2 columns
- having the size of D3 rows & D4 columns
See below examples to understand the formula better.
OFFSET formula examples
Why use OFFSET?
Why not write a reference like A1:C4 directly?
Here are a few reasons why,
- Dynamic ranges: Reference like A1:C4 always refers to the range A1:C4. ie it is static. But sometimes, we want our ranges to be dynamic. This is required because our data is changing (every month new row is added, every time we launch a product new column is added etc.)
- We don’t know the exact address: Sometimes, we don’t know what our ranges actual address is. Rather, we just know it is starting from a certain cell etc. In such situations OFFSET is useful.
Understand OFFSET formula – Interactive Workbook
Since OFFSET formula is somewhat tricky to get, I created an interactive workbook so that you can understand how it works. When you input all the 5 parameters, the workbook highlights the range that your OFFSET will give. After playing with it for a few minutes, you will understand the formula better.
Practical use for OFFSET – Average of latest week
Lets say we monitor quality of a plant producing purple puppets. One of the KPIs we monitor is % of rejected puppets. We have been tracking the % of rejects by day in a spreadsheet that looks like this:
So how do we calculate average of latest week?
Assuming the values are in range C3:C18, we can write =AVERAGE(C12:C18)
BUT, WE NEED TO CHANGE THIS FORMULA EVERYDAY!!!
Even puppets would find that boring.
By using the OFFSET awesome sauce, we can write the AVERAGE formula once and forget about it.
=AVERAGE(OFFSET(C3,COUNTA(C3:C300)-7,0,7,1))
Lets break-apart this formula and understand
- To calculate latest week’s average, we need to go all the to the last data point and then get 7 rows from it and average those values.
- This is where COUNTA(C3:C300) – 7 comes in to picture. It counts how many values are there in column C and then subtracts 7 from it.
- The OFFSET would then starting point from C3 to latest week’s starting point.
- To know how this formula works, watch below demo.
OFFSET limitations
While offset formula can return with a dynamic range when you beckon, it does have few limitations:
- OFFSET formula is volatile: In plain English it means, whenever there is any change in your workbook, OFFSET formula is recalculated, thus keeping Excel busy a tiny bit longer. This is not an issue if you use OFFSET formula in a small workbook. But when you use lots of OFFSET formulas in large workbooks, you will end up cursing Excel as it takes too much time to recalculate.
- OFFSET formulas are tricky to debug: Because the references are dynamic, debugging a workbook with lots of OFFSETs can get tricky quickly.
Alternatives to OFFSET formula
There 2 fine alternatives to OFFSET formula.
- Use Excel Tables: Since Excel 2007, we can create tables from structured data and write formulas, create charts that refer to dynamic ranges with ease. Click here to know more about tables.
- Use INDEX formula: Although not exactly same as OFFSET, INDEX formula can also be used to generate dynamic range references. Plus, INDEX is a non-volatile formula, so it wont keep Excel busy unnecessarily. Know more about INDEX formula.
Do you use OFFSET formula?
For most of my dynamic range needs, I rely on tables or INDEX formula. I use OFFSET formula when I have to calculate values like average of latest week. In such cases OFFSET is an elegant solution.
What about you? Do you use OFFSET formula? In which situations do you use it? Please share your tips & examples with us using comments.
Know More about OFFSET
Check out below examples to understand OFFSET formula better:
- Calculations: Sum of values between 2 dates | Moving averages | Average of closest numbers| More…
- Modeling: Calculate IRR of dynamic ranges | Manage scenario analysis
- Charting & Dashboards: Dynamic range charts | Top x chart | Analyzing large datasets | KPI dashboards
- Validations & Pivots: Dynamic Data Validation | Dependent Drop downs | De-duplicate & Sort data
- And many more uses of OFFSET
37 Responses to “Pie of a Pie of a Pie chart [Good or Bad?]”
If I could have the same quality of graphics and illustration in Office Apps, I would certainly use it.
If I could have the same quality of graphics in Office Apps (Excel, PPT) I would certainly use it.
Chandoo,
First, let me say I love your blog. I like this post, and I think that technically (in terms of readability of data) your argument is correct. The bar of bars, and the table, are much better for readability and accuracy, and as you say would be much easier to produce.
But these points ignore the context of the chart. If the chart was part of a scientific paper, your solution would be a valid one. The context in this case is an illustrated atlas of wildlife. A companion graphic to go with written text. The importance of aesthetic goes up over readability and accuracy. Much of the data and points (I assume) will be covered in the text.
There's always a pure technical tufte-esque argument. But I sometimes think it ignores the value of aesthetics. (Which I admit are quite subjective)
Great post though. Thanks.
The Treemap makes the scope of the data much clearer! The 3D pie chart depiction is deceptive.
This reminds me of the videos ive seen on the internet where it compares the relative sizes of the earth with the larger planets, then the sun, then other stars in the galaxy. Eventually there is an image showing the largest star in the sky with a little pixel representing the sun.
My point is if you varied the size of the charts it would help convey the message. The first chart (salt vs fresh) would be the biggest and the rest would be arranged in descending order. I feel this would be more accurate.
It may be helpful to consider the advice of Steven Few and Edward Tufte regarding pie charts in general. To summarize, they are seldom the most useful way to present data. Here's Few's thoughtful piece on the subject.
http://www.perceptualedge.com/articles/08-21-07.pdf
Try putting the percentages on the bar charts instead of actual amounts. Lakewater would be .013 % instead of 52.
That is very good pie chart example.
Please send example file if it is possible.
It will work , even though colors may be confusing , it can be labeled well . Also it can be called as the drilled chart , as it drills in information further , like the first chart may show business in a region , second may drill into a particular region , thrid may further drill into wat products are there in that region . It works well for me , i would more vote for the 2 nd option .
Overall all this site is awesome ,
p.s : just like me
The risk with pie of a pie of a pie chart is that Jon may have a seizure by looking at it. Also, it isn't easy to read. 😉
I dunno. The only thing worse than a pie chart is a cascading series of pie charts. I don't even think they really lend themselves to this sort of thing. It just becomes a big hide-the-ball game with your viewer.
Those goofy connectors between the pies are pure chart junk. I can't really tell if the second chart has 2 series or 3 - because the connector is a different color than the 2 labeled slices. Despite that, even whereas the drill down kind of works, still the individual components suffer from the same old weaknesses that 3d pie charts have.
Use a large bar chart as your "cover story", and fill in the sub points with smaller bar charts - or even go grab the Fabrice SFE project for extra butter. Use page orientation, color, and some text styles to guide your audience through the drill downs.
FWIW, if you check out the guy's site, you can find several other truly mortifying charts:
http://www.andrewdavies.com.au/index.html
The methane emissions one is particularly heinous. Although, I'm kind of debating what I think about the 'Glacier Changes" chart. I'd kind of like to see the data on that to see how it would look in a more traditional horizon chart.
Thank you, that was scary. I don't understand the "Glacier changes" Chart at all...
Its a very nice way to represent the data, especially when we have sets and sub-sets within the data.
I like these!
Except for the fact that they aren't dynamic and hence must be setup manually each time
It would also be nice if they could be interrogated as in select a different segment and the new data falls out automagically, but then none of the standard Excel charts do that either.
I'd like it better if the bars were stacked. How about this idea (I hope I can convey it in words):
First bar is vertical and stacked.
Second bar is horizontal, stacked horizontally and the same proportion had it been on the first bar.
Third bar is vertical, stacked vertically and the same proportion had it been on the second bar.
Then it would really look like you are zooming on the chart, like the Powers of Ten video, or maybe like the golden ration spiral.
These looks shunting but setting up for each step makes kicks them out. However if these can be arranged automatically by native excel or by VBA, these will be the part of my "Archery"
I agree with Chandoo's Suggestion about the Bar Graph which represents data in a very appropriate manner. Even I prefer doing the same. I seldom use Pie Chart unless required.
That's a real nice example of a missleading infographic. But to be honest, I think chandoos suggestion is not much better!
Why are pie charts bad? I think because they don't show the real size-relations. The biggest pie in that example ist 300k big. The 2nd one has only the size of 10k, about 3% of the first one. Niether the pies nor the bars show the real sizes. I jnow, it's hard to show the sizes because the values of the second and the third pie are so small. But that's what visualization are about - showing relations to allow the reader to see the real sizes!
So how to show the real figures?
First possibility is o use a 1:1 scaling. Well then, you need a very big screen to show also after a 90° rotation, wihich I would prefer because it's a structural comparison and not a timeline. Maybe that solution is not the perfect way.
The other chance you have is to zoom in but to really show that you zoom in! http://www.pro-chart.de/images/Water_Fall.png maybe gives you a first impression what i mean. (i was a quick try, done in 10 minutes)
The next way is, maybe to fold the bars like in the financial report 2011 of the Post of Switzerland page 22. That chart is based on an excel chart. Maybe can explain you how to do it 😉
Financial Statement: http://www.post.ch/en/post-startseite/post-berichterstattung/post-berichterstattung-service/post-berichterstattung-downloads/post-gb-2011-finanzbericht.pdf
page 22: http://www.pro-chart.de/images/FS_Schweizer_Post.png
A way that is not so very common is to divide the bars in a lot of single datapoints. So maybe the 390k bar then consists of about 5,000 single datapoint. That's not possible - it is! Have a look:
http://www.pro-chart.de/images/Dotted_WF.png
It's pure excel!
Now one single point ist 0,2% of the whole (in the example above). Add more datapoints and you can visulize the very big and the very small numbers!
Wish you a lot of fun - visualizing with excel can be very powerful!
Joerg
...if you would like to know how these charts work, just send an email to J.Decker@pro-chart.de
Hey Joerg,
I don't dig so much the dotted waterfall thing. But this is kind of awesome:
http://www.pro-chart.de/images/FS_Schweizer_Post.png
Can you help me on the bar of bar graph? Would it be possible to create that from pivot table? Can you show me how to create the bar of bar graph?
do nothing but say "Awesome!"
You are a Rock star.....This seemed an answer as if someone was reading my mind and just had the solution to my questions on what I exactly was looking for .....What a Fab !!
can u explian me step by step
Can anyone please explain how to make this chart please.
Do you mean the pie of a pie chart or the folded bar chart?
Joery PIE OF PIE Chart please
Can someone please explain how to make PIE OF PIE Chart.
@Mandeep
The last line of the post is:
PS: If you want to know to create this pie of pie of pie chart in excel, see here.
Due to forum migration, link is now:
http://chandoo.org/forum/threads/multiple-pie-chart.7343/
Hi... i love these charts.... can any one show me how to draw these charts in excel 2010
@Vamshi
The very last line of the post refers you to:
PS: If you want to know to create this pie of pie of pie chart in excel, see here. http://chandoo.org/forums/topic/multiple-pie-cahrt
Where is the attachment....it used to be there...i have seen this before but now i am not able to find...
See this:
http://img.chandoo.org/playground/WaterDistribution-chandoo.xlsx
And this:
http://chandoo.org/forum/threads/how-do-you-create-this-chart.9743/
Normally I don't learn post on blogs, however I would like to
say that this write-up very compelled me to try and do so!
Your writing style has been amazed me. Thank you,
quite great article.
This is very impressive, I would like to learn how to build this for myself. I have tried for some time now, is there a step by step process on how to create these waterfall pie of pie charts?
I am novice to excel and use it very seldom. But your blog contains to the point information one needs to get going.
I was searching for a trick to do a Pie chart drill down - for example the first pie chart shows how the prices are distributed between perishable and non-perishable items.
Now if we want to know how the perishable items are distributed - one can click the segment and it will draw another pie chart with distribution of all different perishable items (milk,meat,fruit,veg etc)
So do you have any such trick?
Regards,
electrojit
I like the look of your pie of pie of pie chart, although I understand that the relative size of each pie does not represent the actual percentages.