Get Active in Our Amazing Community of Over 457,000 Peers!

Schedule mock interviews on the Meeting Board, join the latest community discussions in our Consulting Q&A and find like-minded Case Partners to connect and practice with!

Hi everyone, Are there any tips for calculating pourcentages??

Case Interview Math tool
Recent activity on May 23, 2017
2 Answers
3.2 k Views
Anonymous A asked on May 18, 2017


Overview of answers

  • Upvotes
  • Date ascending
  • Date descending
Best answer
replied on May 18, 2017
Former McK Associate Partner / Interviewed 200+ candidates at McK / Specialist McK interviews


I always use a very simple method.

Take 10% as your anchor, if needed 1% as second anchor

I give you a couple of examples

- 157/533 then you calculate the 10% of 533=53. Then from 53 to 157 you aprox multiply by 3 -> then 30%

- 12/327 then you calculate the 10% of 327=33. But 33 higher than 12, so I take the second anchor (1%) 1% is 3.3. Now to get from 3.3 to 12 I multiply by a bit less than 4. So the percentage should be around 3.5%

Practice and it becomes easy!!



Was this answer helpful?
Ramon on May 19, 2017

Such a trick! Gosh. Gracias Carlos


NIHAL on May 19, 2017

WOW greaaat tip !! Curious to know if you have other tips for multiplication or division ? This is really helpful

Anonymous replied on May 23, 2017


I have some students who struggle with this, usualy it is because they need help visualising the question. I like to bring money into examples (they become more real).

Think of $100 as 100% of your savings. Your friend is asking you for 50% or half = so 100/50=2, that means you need to divide $100/2 to get 50%.

If your friend is less greedy and only wants 10%, same principle = 100/10=10; $100/10 =$10 dollars. I draw a little matrix when I do calcs with that same formula and try to visualise, what are they asking from me, what am I calculating etc.

If you can visualise the problem, it becomes less complex.

Hope this helps.

Was this answer helpful?
Carlos gave the best answer


Former McK Associate Partner / Interviewed 200+ candidates at McK / Specialist McK interviews
Q&A Upvotes
2 Reviews
How likely are you to recommend us to a friend or fellow student?
0 = Not likely
10 = Very likely
You are a true consultant! Thank you for consulting us on how to make PrepLounge even better!