How to set up a percentile calculation?
Make sure your questionnaire is completed then head straight to the Extra Options tab and set up your custom score.
Select Formulas in the Custom Scoring section, Click Create formula and add your formulas. For the percentile calculation, you'll need the following formulas and variables:
1 Calculate your scores per section
Build your formula by using the circled symbols to put your formula together. Or click Variables to access the drop-down menu of questionnaire variables that you can use in your formula.
Add up the custom score values for each question to be able to rank your respondent's score.
2 Specify the rank order
Select a Formula to rank in order - this variable ranks the responses from the highest to the lowest.

3 Specify the total number of responses
The response count of the questionnaire gives you the number of respondents who took your questionnaire. This formula collects the total number of respondents.

4 Calculate the percentile
The rank order divided by the response count, multiplied by 100, will give you the percentage score. If you don't multiply it by 100, your results will show a number, e.g. you score better than 3/10 respondents.
5 Final Screen
Set up your final screen and don't forget to add your final formula! You can use the same variables in your PDF report.

Read the full guide about Formulas.
That's all! Now log in and try out the formulas feature for yourself!