Finance gurus - how come this isn't working? Little help :)

Al Neri

Diamond Member
Jan 12, 2002
5,680
1
81
Can someone explain this to me?

I want to invest a steady stream of income from the day my child is born then every birthday until they are 17 - so I can pay for their first year of college which will be 60,000. n.b. i am estimating a 10% return.

i set up a timeline

1---17 would have a steady payment, then the 18th birthday i want 60,000, so that would mean I'd want to have 54,545.4545454 by their 17th birthday. So I do:

Rate=10%
nper=18
pv=0
FV=-54545.5454545454
type=1 (payments are distributed at the beginning of each period)

=PMT(10%, 18, 0, -54545.45454545454, 1)

to which I get 1,087.4490358

Now, when i expand out the math, I get @ the 17th birthday 53,995.8066617... why am i ~500$ short?

no dumb answers like you bought some clothes with it :thumbsup:

Thanks!


 

krunchykrome

Lifer
Dec 28, 2003
13,413
1
0
I dont know.

Just do it the easy way. Use PV/FV tables.

The answer is: You want to invest $11,870.xx the day she is born.

This answer is based on the following conditions.

i=10%
n=17
Interest is compounded annually
 

KLin

Lifer
Feb 29, 2000
30,631
882
126
Order of operations. Make sure you're adding the values from period to period before tacking on the interest.

In excel, I populated Column A with 18 rows of 1087.449

In column B, I put "=A1*(1.1)" for the first row. Every row after that in column B I used "=(A1+B2)*(1.1)" where the row value increment by one.
 

Al Neri

Diamond Member
Jan 12, 2002
5,680
1
81
Originally posted by: krunchykrome
I dont know.

Just do it the easy way. Use PV/FV tables.

The answer is: You want to invest $11,870.xx the day she is born.

This answer is based on the following conditions.

i=10%
n=17
Interest is compounded annually

Did you read the question?:confused:

a steady stream (not lump sum) of payments from the birth to the 17th birthday. 0 to 17 inclusive would make n=18

:confused:

Thanks :D
 

krunchykrome

Lifer
Dec 28, 2003
13,413
1
0
Originally posted by: Don Rodriguez
Originally posted by: krunchykrome
I dont know.

Just do it the easy way. Use PV/FV tables.

The answer is: You want to invest $11,870.xx the day she is born.

This answer is based on the following conditions.

i=10%
n=17
Interest is compounded annually

Did you read the question?:confused:

a steady stream (not lump sum) of payments from the birth to the 17th birthday. 0 to 17 inclusive would make n=18

:confused:

Thanks :D

Sorry, Im a little confused with the question.

 

Viper GTS

Lifer
Oct 13, 1999
38,107
433
136
I just googled & grabbed the first investment calculator, starting balance of $0, 18 year investment period. $100 a month will put you over $60K assuming 10% annual interest.

Your monthly deposit for 18 years of $ 100.00 for an interest rate of 10.000 % compounded annually with an initial amount of $ 0.00:


Year Balance
0 $ 1,256.56
1 $ 2,644.69
2 $ 4,178.18
3 $ 5,872.25
4 $ 7,743.71
5 $ 9,811.13
6 $ 12,095.04
7 $ 14,618.11
8 $ 17,405.37
9 $ 20,484.50
10 $ 23,886.05
11 $ 27,643.79
12 $ 31,795.01
13 $ 36,380.92
14 $ 41,447.03
15 $ 47,043.64
16 $ 53,226.28
17 $ 60,056.32


Final Savings Balance: $ 60,056.32

Viper GTS
 

Ns1

No Lifer
Jun 17, 2001
55,420
1,600
126
TV5 says

1345.32 deposited 17 times will net you 54545.58 + 5454.42 in interest on the last year, for a total of 60k
 

Ns1

No Lifer
Jun 17, 2001
55,420
1,600
126
Compound Period: Annual

Nominal Annual Rate: 10.000%


CASH FLOW DATA

Event Date Amount Number Period End Date
1 Deposit 10/2/2007 1,345.32 17 Annual 10/2/2023
2 Withdrawal 10/2/2024 60,000.00 1


AMORTIZATION SCHEDULE - Normal Amortization

Date Deposit Withdrawal Interest Net Change Balance
Deposit 10/2/2007 1,345.32 1,345.32 1,345.32
2007 Totals 1,345.32 0.00 0.00 1,345.32

Deposit 10/2/2008 1,345.32 134.53 1,479.85 2,825.17
2008 Totals 1,345.32 0.00 134.53 1,479.85

Deposit 10/2/2009 1,345.32 282.52 1,627.84 4,453.01
2009 Totals 1,345.32 0.00 282.52 1,627.84

Deposit 10/2/2010 1,345.32 445.30 1,790.62 6,243.63
2010 Totals 1,345.32 0.00 445.30 1,790.62

Deposit 10/2/2011 1,345.32 624.36 1,969.68 8,213.31
2011 Totals 1,345.32 0.00 624.36 1,969.68

Deposit 10/2/2012 1,345.32 821.33 2,166.65 10,379.96
2012 Totals 1,345.32 0.00 821.33 2,166.65

Deposit 10/2/2013 1,345.32 1,038.00 2,383.32 12,763.28
2013 Totals 1,345.32 0.00 1,038.00 2,383.32

Deposit 10/2/2014 1,345.32 1,276.33 2,621.65 15,384.93
2014 Totals 1,345.32 0.00 1,276.33 2,621.65

Deposit 10/2/2015 1,345.32 1,538.49 2,883.81 18,268.74
2015 Totals 1,345.32 0.00 1,538.49 2,883.81

Deposit 10/2/2016 1,345.32 1,826.87 3,172.19 21,440.93
2016 Totals 1,345.32 0.00 1,826.87 3,172.19

Deposit 10/2/2017 1,345.32 2,144.09 3,489.41 24,930.34
2017 Totals 1,345.32 0.00 2,144.09 3,489.41

Deposit 10/2/2018 1,345.32 2,493.03 3,838.35 28,768.69
2018 Totals 1,345.32 0.00 2,493.03 3,838.35

Deposit 10/2/2019 1,345.32 2,876.87 4,222.19 32,990.88
2019 Totals 1,345.32 0.00 2,876.87 4,222.19

Deposit 10/2/2020 1,345.32 3,299.09 4,644.41 37,635.29
2020 Totals 1,345.32 0.00 3,299.09 4,644.41

Deposit 10/2/2021 1,345.32 3,763.53 5,108.85 42,744.14
2021 Totals 1,345.32 0.00 3,763.53 5,108.85

Deposit 10/2/2022 1,345.32 4,274.41 5,619.73 48,363.87
2022 Totals 1,345.32 0.00 4,274.41 5,619.73

Deposit 10/2/2023 1,345.32 4,836.39 6,181.71 54,545.58
2023 Totals 1,345.32 0.00 4,836.39 6,181.71

1 10/2/2024 60,000.00 5,454.42 54,545.58- 0.00
2024 Totals 0.00 60,000.00 5,454.42 54,545.58-

Grand Totals 22,870.44 60,000.00 37,129.56 0.00



Last interest amount decreased by 0.14 due to rounding.
 

Epic Fail

Diamond Member
May 10, 2005
6,252
2
0
You miscalculated during the expansion, 1087.45 gets you 60k.

Even rounding down to 1087 gets you 54522.93 and not 500 off.
 

Ilikepiedoyou

Senior member
Jan 10, 2006
685
0
0
You can use a Sinking Fund Factor

A=how much should be invested at the end of each period
i=interest
n=years

A=F(i/(x-1)) where x = (1+i)^n

F is the amount you want to reach after n periods at interest rate i

if you are putting money in daily, divide i by 12 and multiple n by 12