How to save percentage as a variable in DAX

[GoingIncognito]

Hi.

My question is simple: How do I save a percentage as a variable in DAX? In order to count Sharpe's ratio I'd need to perform a following calculation:
Profit - (-0,25%) / volatility. How do I save the -0,25% as a variable? Only way I figured was to make a measure containing -0,25 and then change the data type to percentage.

Thank you!

[rajulshah]

Hello @GoingIncognito,

You can either save the format as Percentage:

VAR PercentValue = FORMAT([Your Expression],"Percent")

But if you want to use that variable in a calculation, you can use it like:

VAR PercentValue = [Your Expression]*100

Let me know if this is not what you want.

[GoingIncognito]

Do I follow your reasoning if I say that, Format() returns a string (eventhough I want a number). BUT as DAX is such a high level language, it automagically treats a string as a number when I use it in a calculation? 

[rajulshah]

Yes, FORMAT returns string, you can either multiply by 100 or you can also use VALUE(FORMAT([Your Expression,"Percent")), but not sure if it works. Easiest solution is to multiply with 100.

[rajulshah]

Hello @GoingIncognito, did the solution work for you?

If yes, please mark the answer as solution so that others can find the solution easily.

Thanks.

[GoingIncognito]

The format option doesn't work - unfortunately - and I'm too stupid a person to comprehend how multiplyin by a hundred would help?

[rajulshah]

Didn't understand your question. Can you provide the measure here where you need to convert into Percentage?

[GoingIncognito]

Oh yes, indeed, I should have done so in the first place! Thank you for your patience.

My measure is something like:

Sharpe  =

var risk free interest = (how can I save a percentage value here?)

return
divide( (3,3% - risk free interest ) , 10,8%)

I get the values 3,3% and 10,8% as measures. And for a measure I can set the data format to be percentage. But risk free interest I would like to input as a variable within the measure. How can I save a percentage value to a variable?

[Anonymous · Accepted solution]

I think you need to understand a bit more about how percentages are saved, so here we go.
When a percentage is saved in Power BI it is saved as a decimal number (0,75) = 75%. When you select the modeling as percentage power bi is very smart and knows you want to see 75%. So it does that for you. 
When calculating tho you would (most of the cases) use 0.75. Because if i want to calculate 75% of 1000 i can do 1000*0.75=750.
hence he said you might want to do it *100. (0.75*100=75%)

So to get back to your initial question when you save a measure with -0.25 and make it a percentage. The percentage is -25%. Calulating with -0.25% would be -0.0025.

i hope this helps 🙂

[GoingIncognito]

YES! Of course -0.25% is -0.0025! Silly me for not thinking about this! Thank you so much!

[rajulshah]

Great! @GoingIncognito 

Please mark the answer as solution.

[rajulshah]

@GoingIncognito,

So, if the value is 0.25, if you convert it into Percentage it is 25%, right?

So, you can just do 0.25*100 = 25.

Please let me know if this wasn't clear enough to understand.