Geeks To Go is a helpful hub, where thousands of volunteer geeks quickly serve friendly answers and support. Check out the forums and get free advice from the experts. Register now to gain access to all of our features, it's FREE and only takes one minute. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more.

Create Account How it Works

# Formula to calculate start value (PY)

### #1 Pearle44 Posted 23 November 2009 - 10:45 AM

Pearle44

New Member

• Member
• 2 posts
I have saved this URL as a favourite thinking I will be come very good friend with a lot of you. I hope to contribute back as well.
I am challenged with an Excel formula. I know the end state and % increase but don't know the start value (ie., 10\$ TY at 25% Growth vPY) what is start value for PY?
My co-worker and I have been trying to figure this out for 1 hour, help.
• 0

### #2 Vino Rosso Posted 23 November 2009 - 11:46 AM

Vino Rosso

Visiting Staff

• Visiting Consultant
• 235 posts
I've probably missed what you're looking for but...

if x * 1.25 = y then x = y/1.25

So if you don't know what you started with (x) but know that x grew at 25% and ended at \$10 then...

x * 1.25 = 10 then x = 10/1.25 = \$8

So you started with \$8

Now you can tell me I've misunderstood!
• 0

### #3 Pearle44 Posted 23 November 2009 - 12:00 PM

Pearle44

New Member

• Topic Starter
• Member
• 2 posts
Yes, you are absolutely right. How would you write that in an excel formula?
Hope you are having a super day, you just made mine.
• 0

### #4 Vino Rosso Posted 23 November 2009 - 01:09 PM

Vino Rosso

Visiting Staff

• Visiting Consultant
• 235 posts
Well, it will depend on the formatting used in your spreadsheet but, in general terms, you could try something like:

A1 = Original Unknown value
B1 = Percentage increase (growth) typed as a number e.g. 10% is just 10
C1 = Resulting value typed as a number e.g. \$10 is just 10

In A1 type, =C1/(1+(B1/100))

If you type 25 in B1 and 10 in C1, you'll get 8 in A1.

Now mess about with the cell format to get currency, etc.
• 0

### #5 Jonesey Posted 24 November 2009 - 05:19 AM

Jonesey

Member

• Member
• 335 posts
And if you really want, we can introduce compound interest at a later stage!
• 0

### #6 Vino Rosso Posted 24 November 2009 - 01:47 PM

Vino Rosso

Visiting Staff

• Visiting Consultant
• 235 posts

And if you really want, we can introduce compound interest at a later stage!

Show off!!
• 0

### Similar Topics

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users