I have looked online for a calculator to figure this out but I can't find one that will let me input the info I want.

Assumptions

-I live to age 90

-I need $24,000/year to live on from now until then (I am 34 now)

-4% rate of return on investment

-I receive $1400/month from government, between age 65-90

Is there a calculation I can do that will tell me I need to invest $_________ if I want to stop working at age __________.

Short answer:

Retire

at Requires/yr40 $62,886

45 $27,991

50 $15,088

55 $8,466

60 $4,498

65 $1,896

Done using Excel's PMT and FV functions, some extra input cells on the 'Misc. calcs' tab of the

case study spreadsheet, and Excel's Goal Seek feature.

If you are interested in a summary of the gory details...:

1) Added input cells for the items below

`Age now 34`

Stop at age 40

SS start 65

SS benefit 16800

Need 24000

Death 90

2) Used 4%, 1, and 0 respectively for rows 18, 20, and 21 in columns C, D, and F

3) Entered formulas for row 19, using the "added input cells" above

4) Put "=F22" in C16 and "=D22" in D16.

5) Picked a number for "Stop at age"

6) Used Goal Seek to drive cell D22 to 0 by adjusting cell F22.

There are probably easier ways. :)

Note that this assumes steady returns, and thus ignores "sequence of returns" risk. But it gives you a ballpark....