Lets say you have a large list of numbers, and you want to calculate the average of every nth value. Not the average of all numbers, but just every nth number.
That is what we will learn in next few minutes.
Few assumptions
Before we jump in to any formulas, first lets assume that all your data is in a table, conveniently named as tbl. Lets say this table has below structure.
Also, the value of n is a named cell N.
Average of every nth value
Approach 1: Using helper columns
If you have no allergies towards nuts, dairy or helper columns, then this approach is easiest.
We just add an extra column to our tbl , called as helper.
In the helper column, write this formula.
=MOD([@ID], N)=0
This will fill the helper column with TRUE & FALSE values, TRUE for all nth values, FALSE for everything else. See aside.
Once we have the helper column, calculating average of every nth value is easy as eating every slice of a cake.
We use AVERAGEIF to do this.
=AVERAGEIF(tbl[Value],tbl[Helper],TRUE)
Approach 2: Not using helper columns
Now things get interesting. Lets say you want to calculate average, but not use any helper columns.
First the formula:
=AVERAGE(IF(MOD(tbl[ID], N)=0,tbl[Value]))
Array entered.
Lets understand how it works:
We want the average of every nth item of tbl[Value] column.
In other words, we want average of every item of tbl[Value] column, whose corresponding tbl[ID] value is perfectly divisible by n.
How do we know when a value is perfectly divisible by another?
Don’t worry. You don’t have to do the long division on paper now. Instead we use Excel’s MOD function.
When a value is perfectly divisible by another, the reminder is zero.
So, MOD(value1, value2) = 0 means, value2 divides value1 perfectly.
That means…
We want the average of tbl[Value] when MOD(tbl[ID], N) = 0
Lets write that in Excel formula lingo.
=AVERAGE( IF(MOD(tbl[ID], N) = 0, tbl[Value]) )
This formula results in a bunch of values and FALSEs. Assuming N=3, this is what we get (for sample data):
=AVERAGE({FALSE;FALSE;15;FALSE;FALSE;18;FALSE;FALSE;18;FALSE;FALSE;15;FALSE;FALSE;14; …})
Since AVERAGE formula ignores any logical values, it will calculate the average of {15, 18, 18, 15, 14 … } and returns the answer you are expecting.
As this formula is processing arrays instead of single values, you need to array enter it (CTRL+SHIFT+Enter after typing the formula).
Bonus scenario: Average of FEBRUARY values only!
Here is a bonus scenario. Lets say you want to calculate the average sales of FEB alone… Then you can use AVERAGEIF (or AVERAGEIFS, if you want to have multiple conditions).
=AVERAGEIF(tbl[value], tbl[month], “FEB”)
Download example workbook:
Click here to download the example workbook. It contains all the techniques explained in this post. Play with the data & formulas to understand better.
Time for some challenges…
If you think averaging every nth value is not mean enough, try below challenges. Post your answers using comments.
- Write a formula to calculate average of every nth value, starting at row number ‘t’.
- Write a formula to calculate average of every nth value, assuming your table has only value column (no ID column).
Go ahead. Show off your formula skills. Post your answers in comments section.
Improving your Excel batting average
Calculating averages predates slice bread. Folklore says that when first neanderthal figured out how to express numbers and carved 2 of them on a cave wall, his manager walked by and asked “What is the average of these two? Eh?” and thumped her chest.
Although caves & wall carvings are replaced by cubicles & spreadsheets, we are still calculating averages, almost 2.9 million of them per hour.
So it pays to learn a few tricks about Excel Average formulas. Check out below to improve your average:
- Calculating Moving Average, Weighted Average
- Average of top 5 values
- Show averages & distribution in your charts
- Using SUMIFS formula (same tricks apply to AVERAGEIF, AVERAGEIFS too)
If your boss is the kind who thumps her chest and mocks you for your poor Excel skills, don’t cave in. Fight back. Enroll in Excel School and show that you can evolve.
18 Responses to “Best Charts to Compare Actual Values with Targets – What is your take?”
Great post. I can't vote, though, because the answer I want to put down is "it depends". As with all visualisations, you've got to take into account your audience, your purpose, technical skills, where it will be viewed, etc.
I'm with Andy: It depends. Some I would use, some I might use, some I won't touch with a barge pole.
Naturally I have comments 🙂
The dial gauge, though familiar, is less easy to read than a linear type of chart (thermometer or bullet). It's really no better than the traffic lights, because all it can really tell you is which category the point falls in: red, yellow, or green.
By the same token, pie charts are so familiar, people don't know they can't read them. Remember how long it takes kids to learn to read an analog clock?
Bullet charts don't show trends.
With any of the charts that have a filled component and a marker or ine component, it makes more sense to use the filled component (area/ column) for target, and the lines or markers for actual.
[...] Best Charts to Compare Actual values with Targets (or Budgets … [...]
I voted for #6 even though I agree with the other comments that it depends.
The majority of the votes are for the #2, thermometer chart. I still have yet to understand what happens when you are above plan/goal, which was brought up in yesterday's post.
Also, I agree with Jon in that it would be better to flip the series and make the filled part the target or goal and the line or marker the actual.
I am also a fan of using text when appropriate if the data is among other metrics in a type of dashboard. Calling it out by saying actual and % achievement is a good option.
Another "it depends" vote. Are you just looking at one or are you comparing a number of targets with actuals? You didn't include a text box. The problem with sentences is that they can get lost in a page of gray text. A text box can call attention to the numbers and line them up effectively.
I'm with Jon: "Some I would use, some I might use, some I won’t touch with a barge pole" and I'm surprised that some of your readers voted for the last group.
Jon says:
With any of the charts that have a filled component and a marker or line component, it makes more sense to use the filled component (area/ column) for target, and the lines or markers for actual.
Why does this make more sense? I like 6 the way it is, although I would use a heavy dash for the plan/target marker.
"It depends" is also my take. What I usually try to drill into my clients dashboard design is the fu ndamental difference between spot results (am I on target for this month) and long term trends.. I always try to create 3 different set of graphs to represent real perormance:
- spot results vs objectives
- cumulative results vs objectives
- long-term trend (moving average) mostly) to see where we're going
[...] Best Charts to Compare Actual Values with Targets – What is your take? (tags: excel charts) [...]
[...] Related: Charting Principles, How to compare actual values with budgets [...]
[...] Excel Charting Alternatives to compare values [...]
Jon says:
With any of the charts that have a filled component and a marker or line component, it makes more sense to use the filled component (area/ column) for target, and the lines or markers for actual.
Why does this make more sense? I like 6 the way it is, although I would use a heavy dash for the plan/target marker.
I totally agree, Bob. I would normally favour a line for the target and a column for the actual, you can see quite easily then which columns break through the line, then.
[...] best charts to compare actual values with targets — den Status mal anders zeigen, z. B. als Tacho [...]
Thermometer charts: "Not appropriate when actual values exceed targets" - this is easily solved by making the "mercury" portion a different color from the border, then you can clearly see where the expected range ends and the actual values keep going.
People seem to knock gauges quite a bit in dashboarding, but trying to show comparison of realtime data between operating sites and targets for each site can easily be done with a bank of gauges that have the optimal operating points at 12 o'clock.
The human eye is great at pattern stripping, and any deviation of a gauge from the expected 12 position will quickly register with an operator and attract his attention. Using a colour background, or meter edge, will also indicate the sensitivity of a particular site.
[…] Best charts to compare actual with target values […]
[…] Best charts to compare actual with target values […]
[…] work laptop I have a favorites folder just dedicated to Excel charts. Its got things like “Best Charts to Compare Actuals vs Targets” and “Best charts to show progress“. I love me some charts […]
I am wondering how will the plotting work, for some of the targets which may have been achieved before time. E.g. for the month of Jul the target was 226 and the actual was 219. So the chart will show a deficit in meeting the target by 7 points but what if this 7 may have been completed earlier in month of June. So ideally it not a deficit.