Bar chart or Line? Scatter plot or box plot? These are the questions we ask ourselves when we set out to make a chart. In this article let me tell you how to pick a chart type so you can make best charts for every situation.
Why is it important to pick right chart?
Because right charts lead to right decisions. We use charts to tell stories, evaluate alternatives, understand trends or find-out if everything is normal. So, an incorrect charting choice can lead to poor judgment of the messages where as a correct chart can lead to right and faster decisions.
How to pick a chart type:
Chart making process can be divided in to 4 steps
- Find-out what you want to say?
- (Re)arrange the data
- Prepare the chart
- Format the chart
1. What is the purpose of this chart?
This is the first and most important step in chart preparation. You must ask yourself, “what is the purpose of this chart?”. Once we know the clear reason why the chart should exist, we will naturally be able to select the correct chart type for that reason.
But I realize that finding the reason itself can be a bit tedious. So I have listed down 6 common reasons that we often have to make a chart:
- to Compare
- to show the Distribution
- to explain Parts of the Whole
- to tell the Trend over time
- to findout the Deviations
- to understand the Relationship
Let us understand these reasons along with the type of charts that go well with these.
1. To Compare:
What it means? You want to compare one set of value(s) with another.
Examples:
- Performance of Product A vs. Product B in 5 regions
- Interview performance of various candidates
Charts that can be used for this reason:
- Bar Charts,
- Column Charts
- Scatter Plots
- Pie Charts
- Line Charts
- Data Tables
2. To Show the Distribution
What it means? You want to show the distribution of a set of values (to understand the outliers, normal ranges etc.)
Examples:
- Distribution of Call waiting times in a call center
- Distribution of bugs found in 10 week software testing phase
Charts that can be used to show distribution:
- Column Charts
- Scatter Plots
- Line charts
- Box Plots
3. Parts of Whole
What it means? You want to show how various parts comprise the whole
Examples:
- Individual product sales as a percentage of whole revenue
- Browser types of customers visiting our website
Charts that can be used to show Parts of Whole:
- Column Charts
- Bar Charts
- Pie Charts
- Data Table
4. Trend over time
What it means? You want to understand the trend over time of some variable(s).
Examples:
- Customer footfalls on the last 365 days
- Share price of MSFT in the last 100 trading sessions
Charts that can be used to show Trend Over Time:
- Column Charts
- Line Charts
- Data Table
5. Deviations
What it means? You want to see which values deviate from the norm.
Examples:
- Failures (or bugs) in the context of Quality Control
- Sales in Various Stores
Charts that can be used to show Deviations:
- Column Charts
- Bar Charts
- Line Charts
- Data Table
6. Relationship
What it means? You want to establish (or show) relationship between 2 (or more) variables
Examples:
- Relationship between Search Phrases and Product Purchases in your website
- Relationship between in-store sales and holidays
Charts that can be used to show Relationship:
- Scatter Plot
- Line Chart
- Data Table
How to pick a chart type when you have more than one reason for the chart?
Simple, use common sense. If I were you, I would either cut down the messages to one or make 2 charts (each conveying one message). If that is not possible, I would consider using dynamic charts or combination charts.
2. (Re)arranging the Data
Even when we know the message and corresponding chart, sometimes, our data may not support us. We then have to rearrange the data. Using excel formulas, pivot tables, tables and data cleaning tools we can easily massage the data.
Once we have the data in required format, we proceed to step 3.
3. Prepare the chart
Since you have already picked the chart type in Step 1, this is very straight forward. Most of the regular charts are available in MS Excel as default charts. You can insert them with few clicks.
But for some special chart types, you may have to prepare the chart by helper series, formatting etc.
4. Format the chart
While most formatting is done as per individual taste, there are some ground rules that apply on almost all charts. Here they are,
- No non-zero axis scale on bar charts [reasons and discussions]
- Make subtle grid-lines (or remove them) [how to remove grid lines]
- Add labels to important points [labeling techniques]
- Add descriptive, bold titles
- Position axis, scales at the right places (for eg. y-axis to the right on a large time series chart)
- Use simple, easy colors
A final word:
The ideas in this post are meant to be guide lines, not final words in the world of visualization. While these rules can help you make a good chart, a great chart take so much more. Knowledge of your data, Passion for what you do and Genuine focus on your audience’ needs can make your chart truly outstanding. All the best.
References:
Communicating Numbers – White Paper by Stephen Few [PDF]
Resources & Further Help:
- Chart chooser – Juice Analytics
- Data vis 101 – How to choose a chart – Hubspot
- Selecting right char type – KD Nuggets
- Charting Principles
- Charting Tutorials from Peltier Tech
- More articles from Stephen Few
- Charting Wisdom from Jorge Camoes
What is the process you use for Chart Selection?
I would love to know the process you use when selecting a chart type. Please share using comments.
39 Responses to “Make a Quick Thermometer Chart to Compare Targets and Actuals”
You'll probably have some readers insist on bullet charts, which in my experience are no easier to read.
Note on the case where actuals may exceed targets, the target has to be the second series in the chart, not the first, so it appears in front of the actual.
@Jon.. good point. And yes, readers are already saying bullets are the way to go. Atleast @dmgerbino said it on twitter: http://twitter.com/dmgerbino/status/6761754333
But I feel the same as you did. Bullets need orientation to get started and not that easy to construct (here is a tutorial btw... http://chandoo.org/wp/2008/07/21/dashboard-bullet-graphs-excel/ )
When you just have to compare 2 sets of values, a chart like above is good and easy enough.
And yes, thank you for saying that data series order should be correct to show the target on top.
I think bullet charts are a good alternative. I'm not a huge fan of the formatting that you used above where the outline is so thick.
Another option would be to combine a line graph (plan/goal amounts) with the columns (actual) and select the option to remove the line. This leaves just the value (marker), which can be increased in size to leave only a line about the size of the bar. It's an easy and cleaner way to show actual to plan/goal. Does that make sense?
Tony -
I would use columns (or area) for goal, and lines and markers for actual.
What about if you go over the target? The chart doesn't work so well then.
The technique described today is a near bullet chart. As I stated early this morning on Twitter (link: http://bit.ly/4K3yPM ) , I am a fan of Stephen Few's Bullet Graph.
Hubert Urruttia and I started with Charlie Kyd's method, but as Jon Peltier and Chandoo said, they are not easy to contruct. We moved onto prototyping with Fabrice Rimlinger's SPARKLINES FOR EXCEL and now use XLCube's (BonaVista) Micro Chart tool. Both of these tools allow you to create bullet charts just as easy as any Excel chart type.
As far as reading and interpreting them, this chart type has been the easiest for us to present.
There are many chart types. Today's "Make a Quick Thermometer Chart to Compare Targets and Actuals" is fine for a start, but your ultimate goal should be to create Bullet Graphs. AS Stephen Few states in his overview, "The bullet graph was developed to replace the meters and gauges that are often used on dashboards. Its linear and no-frills design provides a rich display of data in a small space, which is essential on a dashboard. Like most meters and gauges, bullet graphs feature a single quantitative measure (for example, year-to-date revenue) along with complementary measures to enrich the meaning of the featured measure. Specifically, bullet graphs support the comparison of the featured measure to one or more related measures (for example, a target or the same measure at some point in the past, such as a year ago) and relate the featured measure to defined quantitative ranges that declare its qualitative state (for example, good, satisfactory, and poor). Its linear design not only gives it a small footprint, but also supports more efficient reading than radial meters."
@dmgerbino
Since @dmgerbino had to bring my name up I guess I should throw in my two cents.
@dmgerbino and I have both implemented Bullet Charts with great success. What is most interesting about this fact is that we have had a harder time implementing Sparklines than Bullet Charts. The reason for this revolves around the simple fact of familiarity. I will explain. People look at a Sparkline and they think it is a really small Line Chart and it is not. People are familiar with Line Charts since they have been around since 1786 when they were created by William Playfair. Bullet Charts on the other hand are different so they almost demand an explanation. Because of this there was a lot of face time that was needed to explain these charts but once people got them they understood the concept. This is similar to when I introduced Cycle Plots http://bit.ly/87ydVG (Thank you @nbrgraphs!) or Horizon Charts http://bit.ly/6PVavj.
Now about the Thermometer Charts… The first thing I want to address is Tony Rose’s statement. I totally agree that the outline on the chart is too think. It might come of as being a whole new series or a new variable. What I have done in instances like this is I have created a Bar Graph and Scatter Plot mixture. Then I have turned off the Data Series on the Scatter Plot and turned on the Horrizontal Error Bars on the Scatter Plot. The new horizontal line stands for the Plan and the Bar is the actual. The reason why I find this more useful is because this technique works if you have exceeded plan. Actually, I do not understand how Chandoo’s method would display the data if Plan is surpassed.
This reminds me of another blog post that @dmgerbino, @Jon_Peltier, and myself commented on over a year ago. http://bit.ly/PNdO Actually, I talk about similar things in regards to familiarity to charting techniques.
- @hubert_urruttia
[...] we have a post on using thermometer charts to quickly compare actual values with targets. Today we follow up the post with 10 charting ideas you can use to compare actual values with [...]
Hi Chandoo
How do I increase the width of the bar chart and also make the long axis labels come in the same line?
Thank you,
Rajiv
@Rajiv
Select the outer part of the chart "Chart Area" and note the cursor will change to arrows
drag the edges to what ever size you want
You can hold the Alt key as you drag and the chart will snap to the cell boundaries
Now click on the chart area inside the chart "Plot Area" and note that a box with small circles appears around it
drag the circles on the edge of that box to suit
You can hold the Alt key as you drag and the chart will snap to the cell boundaries
@ Hui
Thank you for your comments. But my question was not for the "Plot Area" instead I wanted to know about how should I increase the width of the individual bar charts because with my data all the individual bars are coming to be thin and I want to make them appear broader.
Thank You
@Rajiv
Right click on the Series you want to change and select Format Data Series
Under Series Options goto Gap Width and decrease it to suit
[...] Make a Quick Thermo-meter Chart using Excel [...]
Thank you for the great chart and explanation!
How do I show two amounts (Signed Revenue and Pipeline) as stacked within the Target amount?
@CL... you can use stacked column charts and follow the same technique to get this. See attached file for an example - http://img.chandoo.org/playground/thermo-meter-with-additional-details.xlsx
Chandoo - thanks for the quick response! What if I want the data label for the pipeline to be the actual pipeline value, not the signed rev + pipeline value? i.e. 15 instead of 55
Thanks!
How would i do this in excel 2003?
[...] Thermo-meter charts are very good to show how actual value compares with target (or budget). But how can we add another point for say Last Year value to the chart with out cluttering it. [...]
Hi Guys,
As Matt said,
"What if you if you go over the target?"
Is there a way to make it change color? or at least to show what the target was?
I am planning to use this with a "Forecasted vs Real" production chart but I do not know how to show overproduction.
Any clue?
Thanks
How do I do this if I have 2 bars I want side-by-side? ie 2012 Mean with 2012 benchmark overlapping and then 2013 mean with 2013 benchmark overlapping? I want the 2012 and 2012 mean bars sie by side to compare multiple categories.
Sorry, I meant to say the 2012 and 2013 mean bars side by side
I have a problem in that my PM wants a chart that shows a stacked column (Labor and Expense) and then have the overall buget shown as a thermo.
Everytime I try to do this, I either end up with all three being stacked or all of them being seperated.
Help?
Or if someone knows how to only outline the top and sides of a chart series....then I would have this solved. (Make a stacked column with labor, expenses, and remaining budget, then clear the fill and outline only the top and sides.) I just can't figure out how to do that/ not sure if excel will let me only outline part of a chart series.
[...] Thermometer chart to show budget vs. actual performance [...]
Your home is valueble for me. Thanks!...
I've created the thermometer chart as the Chandoo tutorial described. How do I move my columns closer together? I don't want wider columns; I want to move my narrow columns closer together. Thank you!
Dear Elite members,
could you please let me informed whether we could incorporate color formating in this thermometer approach i.e. if my actual performance is <Min then meter color sud go Red, in between min & target it sud change to Amber & target and above sud change to Green. pls advise. thanks,
I think the only way to do that would be with VBA programming.
@Abhinav
Yes, Simply use a stacked column chart, colored appropriately
Or
You may also want to read about Bullet Charts
@ Hui,
Could you pls demonstrate this with the help of an example.
let's have the below sample data
Actual=12
Min=10
Target=15
Max=20
if Actual>=Min then bar color sud be Red
in between Min & Target= Amber
between target(inclusive) & Max = Green
greater than or equal to Max= Blue
Thanks in advance
Abhi
Great blog post with awesome sample data. I've implemented two of the top "power tips" by changing the colour of the actual values, AND setting Actual to be 40% transparent. Looking good.
[…] easy with these charts. Use them sparingly. As a rule a thermo-meter chart would be better (easy to make, takes less space, scalable) for situations like […]
[…] easy with these charts. Use them sparingly. As a rule a thermo-meter chart would be better (easy to make, takes less space, scalable) for situations like […]
I recently purchased the template bundle and love the ease of use - thank you!
I would like to ask if it is possible to add an important 'block' to the dashboard to illustrate an important status for my executive team; 'billing status'? (ie budget / amount billed) something like that?
Thank you!
@Cheif449.. Thanks for your purchase and kind words.
You can add this easily to the dashboard. Follow below steps.
1. Unprotect the dashboard worksheet.
2. Add a text box (Insert > Drawing Shapes) to the dashboard
3. Put any text inside it as per your need.
4. Format it as needed.
5. Protect the dashboard again.
How do you do this in Excel 2010 - I am not seeing that option in Format data series.
how would we check target and actual sale for multiple years
Select any of the bar, right click and format data series