I am trying to create a formula in Excel that solves for the base number of units needed on a monthly interval with an annual growth escalator that matches in whole units the total I'm starting with. I can't from a practical standpoint have fractions.
This is an example of the formula x is number of monthly units, y is the total number of units and the desired annual growth rate is 20%. Here is the algebra butin practice only one variable will need to be solved for (x): y= 12x + (1.2x)*12+(1.2^2)*x*12+(1.2^3)*x*12. I get close using the round function but always end up a few short of the total desired due. Is there a way to add on the difference at the end formulaically?
ROUND(20000/(12+(12*(1+20%))+12*(1+20%)^2+12*(1+20%)^3),0)
I'm extremely close but I need to make sure the total by month matches the total desired.
Related
Here is the spreadsheet download to work from. I'm running on Office 365.
I am trying to get the "Rate" and the "Days Billed" for each record. The amount is a function of Rate x Days Billed. The number of Days Billed max out with the total number of days in each month (i.e. November is 30 days max); these are also whole numbers.
I wrote this formula in E2:
=IFERROR(SMALL(IF(MOD($A2,ROW(INDIRECT("1:"&DAY(EOMONTH($B2,0)))))=0,ROW(INDIRECT("1:"&DAY(EOMONTH($B2,0))))),COLUMNS($E2:E2)),"")
In C2:
=MAX($E2:$R2)
In D2:
=A2/C2
When I drag across it spits out all the whole number divisors (Days Billed) that result in the Amount/Days Billed to also be a whole number. It is only getting me results for whole number Days Billed which also result in whole number Rates when dividing with the Amount. I want to include Rates that go to the hundredths place as well, not just whole numbers. (Rates often go to hundredths place)
For example, if the Amount is $4,832.40 in November the Rate should be $161.08 and the Days Billed should be 30 because 30 days is the max divisor of days and 161.08 is also divisible to the hundredths place.
Each amount basically has a whole number day multiplied by a rate that can be whole number or up to the hundredths place of denomination.
I may be overthinking this, but does anyone have any ideas of how to tweak my formula to achieve what I'm after? or even a better solution? It'd be ideal if I didn't have to have those helper columns either and it was encased in a single cell formula.
Thanks a ton,
spacej3di
Use LARGE instead of SMALL and multiply A1 by 100 and return the max:
=IFERROR(LARGE(IF(MOD($A2*100,ROW(INDIRECT("1:"&DAY(EOMONTH($B2,0)))))=0,ROW(INDIRECT("1:"&DAY(EOMONTH($B2,0))))),1),"")
So I am trying to build an excel model where every month the numbers will increase exponentially to a point at the end of the year which is driven by annual expectations. Currently I have it divided by 12 and each year there are huge jumps over the previous making the chart/growth very jumpy. For illustration purposes, lets say for 2020 the desired number for the year is 12. In the current state, I would get 1 per month (12/12), however, what I want is for it to be growing gradually/exponentially, so for example 0.2, 0.5, 0.9 etc with December being the largest, and the sum for the entire year equaling 12. Then the next year (2021), starting in January, it would take into account the December 2020 number and grow from there again to the desired number (lets say total 24 for 2021) and so on. I'd love for it to have a more exponential / hockey stick-like growth.
What would be a good way to do this?
The function RRI can be used to find an interest rate which will give you a given target value. This can be used to find terms in a geometric series which have a given sum (which is what you seem to be asking for).
For example, say you want 12 exponentially increasing numbers which, when added to 100, gets you to 2000. Starting with 100, repeatedly multiply by (1 + RRI(12,100,2000)). To get the numbers that you want (which will be 12 numbers which sum to 1900) just calculate the difference each month:
I think the simplest way to solve this is by using Goal Seek. First you need to build a sheet like this:
You choose the starting value in January (B1) and every month is a constant growth rate (D1) bigger than the previous month. You also calculate the total sum at the bottom in B13.
Now you use goal seek to find the growth rate which makes the sum equal to 12:
The answer I get for a starting value of 0.1 is a growth rate of 1.376:
I have a simple spreadsheet that calculates the mortgage payment (using PMT) once user enters some key fields. I am also calculating the housing ratio (B9) which is the mortgage payment(B6) divided by income (B7). I am comparing the housing ratio to the maximum housing ratio (B8). There are many times when the housing ratio (B9) exceeds the maximum housing ratio (B8) and I need a formula in cell B11 that will tell me by how much I have to reduce the loan amount in (B3) to NOT exceed the maximum housing ratio in B8.
Can someone help me out with the correct formula?
Being that this is a pretty simple calculations, I'd suggest just doing it manually using iterative calculation.
First, enable iterative calculations for your workbook via File > Options > Formulas > "Enable iterative calculations."
Then, edit the formula for the loan amount to be (sale price * LTV) - reduce by
Doesn't take long the enter a few different numbers in for the "reduce by" to find it needs to be reduced by ~$6786.
If you want to make it a little more clear you can add another row under Loan Amount like so:
I'm trying to calculate a lifetime value of a customer. Let's assume a new customer pays $100K per year and stays for 5 years. Let's discount any future years' payments with 10% rate.
This is manual calculation:
Year 1 $100,000.00
Year 2 $90,000.00
Year 3 $81,000.00
Year 4 $72,900.00
Year 5 $65,610.00
---------------------
Total $409,510.00
I can get the same value by using FV with negative rate.
FV(-0.1,5,-100000,0,0) = $409,510.00
What I'm trying to do is to get the same value using PV. And it's not exactly the same:
PV(0.1,5,-100000,0,1) = $416,986.54
I'm not sure what am I missing here. Does MS Office Excel 2010 PV understand discounting differently?
If you calculate out what PV is doing manually, the formula is actually this, for each individual year:
=Base Amount / (1 + Discount Rate) ^ Periods
Vs what FV is doing manually, the formula is this (which you seem to know based on coming to the same answer in your data):
=Base Amount * (1 - Discount Rate) ^ Periods
The reason for the difference in calculation is the mathematical difference between the two items - for background see here: http://www.investopedia.com/walkthrough/corporate-finance/3/time-value-money/future-value.aspx and here: http://www.investopedia.com/walkthrough/corporate-finance/3/time-value-money/present-value-discounting.aspx.
In short, if you have $100k today, and invest it in something which gives you 10% each year, then each year you add 10% of the current balance to get the new balance. ie: in year 1 you add 100k * 10% = 10k, giving a new total of 110k; in year 2 you add 110k * 10% = 11k, giving a new total of 121k, etc. - Mathematically, each year's amount is given by the formula listed above for the FV calculation.
Where this gets tricky is that you are giving yourself a negative interest rate - meaning every year, the value is decreasing each year by 10%. You have attempted to use the FV calculation with a negative interest rate, but that's not quite correct. What you should be using is the PV formula.
For the PV formula, if you know that you will receive 100k each year, you need to determine how much cash you would have needed originally, in order to earn the same amount - that is the present value of the cash flow stream. Now, you need to 'gross-up' the value of each year's income stream. The formula for this gross-up is derived mathematically and results in what I have above there for PV. Think about it like this - if there's a shirt that normally costs $100 and is now 30% off, you can see that you simply multiply it by 30%, to get $70. But if you see of shirt on sale for $70, and it's 30% off, then to determine the original base price you need to take $70 & divide by .3 - which gives us $100.
To prove to yourself that the PV formula is appropriate, take the income stream of, say, year 4 [3 periods of interest later, assuming first payment is received in day 0]: 100k / (1 + 10%)^3 = $75,131. Now, work backwards - if you want to know the future value of a $75k investment held for 3 periods of interest compounded annually with a 10% annual rate, you go: 75,131 * (1 + 10%) ^ 3 = 100k.
This is an important financial distinction, and you should read over the sources I've linked to ensure you understand it.
There is a difference in the calculation. FV takes 100,000 and discounts it by 10% to the number X so that X is 90% of the original value (i.e. X=90,000). PV by contrast discounts it to the number X such that 100,000 is 10% more than X. Quick math says X will be 10/11 of 100,000, i.e. 90909.09.
Indeed, if we apply this calculation 5 times:
Year 1 $100,000.00
Year 2 $90,909.09
Year 3 $82,644.63
Year 4 $75,131.48
Year 5 $68,301.35
---------------------
Total $416,986.5
I don't know if there is a way to make them behave the same way (I don't think there is, as they're calculating different things), but since FV solves your problem why not just use that?
i have a yearly unit that i divide by a percentage to give me the monthly equivalent. I have a growth formula that increases the monthly unit to a yearly one month by month, how can i create a formula that give me the actual unit per month not the growth. Example
4
5
7
8 this is the growth but i what 5-4=1....
7-5=2...
=ROUND(Q59*$B$49,0) is how i get 4..5..6..7..8 how do i get to 1..2..1 in one formula . Thanks
If I'm understanding you correctly you are looking for the incremental increase rather than the total increase. Without more information it is difficult to understand exactly what your looking for, but your formula sounds like it is multiplying over 100%. You want to multiply by the percentage of increase. so essentially what your doing is adding the beginning balance back in. Change your percentage in the cell to the increase and not the increase plus beginning.