In: Accounting
Matthew has a new job as business analyst. He plans to invest 12 percent of his annual salary after the tax into a retirement account at the end of every year for the next 30 years. Suppose that annual return is 5%, and his current after tax salary is 76k which grow 3% per year then:
1)Create a spreadsheet which shows Matthew the balance of retirement account for various levels of annual investments and returns. (EXCEL)
2)If Matthew aims to gain $1,500,000 at the end of the 30th year, what percentage of his salary he should put in the investment annually.
Amount = Principal (1+r)^t | ||||
Year 1 | Investment in Retirement account(12% of Salary) (P) | Years left(t) | Amount | |
76000.00 | 9120.00 | 29 | 37539.16 | |
78280.00 | 9393.60 | 28 | 36824.13 | |
80628.40 | 9675.41 | 27 | 36122.71 | |
83047.25 | 9965.67 | 26 | 35434.66 | |
85538.67 | 10264.64 | 25 | 34759.72 | |
88104.83 | 10572.58 | 24 | 34097.63 | |
90747.97 | 10889.76 | 23 | 33448.15 | |
93470.41 | 11216.45 | 22 | 32811.04 | |
96274.53 | 11552.94 | 21 | 32186.07 | |
99162.76 | 11899.53 | 20 | 31573.00 | |
102137.64 | 12256.52 | 19 | 30971.61 | |
105201.77 | 12624.21 | 18 | 30381.67 | |
108357.83 | 13002.94 | 17 | 29802.98 | |
111608.56 | 13393.03 | 16 | 29235.30 | |
114956.82 | 13794.82 | 15 | 28678.44 | |
118405.52 | 14208.66 | 14 | 28132.18 | |
121957.69 | 14634.92 | 13 | 27596.33 | |
125616.42 | 15073.97 | 12 | 27070.69 | |
129384.91 | 15526.19 | 11 | 26555.05 | |
133266.46 | 15991.98 | 10 | 26049.24 | |
137264.45 | 16471.73 | 9 | 25553.07 | |
141382.39 | 16965.89 | 8 | 25066.34 | |
145623.86 | 17474.86 | 7 | 24588.89 | |
149992.57 | 17999.11 | 6 | 24120.53 | |
154492.35 | 18539.08 | 5 | 23661.09 | |
159127.12 | 19095.25 | 4 | 23210.40 | |
163900.94 | 19668.11 | 3 | 22768.30 | |
168817.96 | 20258.16 | 2 | 22334.62 | |
173882.50 | 20865.90 | 1 | 21909.20 | |
179098.98 | 21491.88 | 0 | 21491.88 | |
TOTAL | 433887.79 | 863974.04 | ||
Principal | 433887.79 | |||
Amount at end of 30 years | 863974.04 | |||
Total Return (A-P) | 430086.245 | |||
We calculate by using future value of growing annuity formula. FVGA = P*{[(1+r)^n - (1+g)^n]/(r-g)} FVGA = 1500000, r = 5%, g = 3%, n = 30, P = First Payment | ||||
P = 15833.84 | ||||
Amount = Principal (1+r)^t | ||||
Year 1 | Investment in Retirement account(20.834% of Salary) (P) | Years left(t) | Amount | |
76000.00 | 15833.84 | 29 | 65174.23 | |
78280.00 | 16308.86 | 28 | 63932.82 | |
80628.40 | 16798.12 | 27 | 62715.05 | |
83047.25 | 17302.06 | 26 | 61520.48 | |
85538.67 | 17821.13 | 25 | 60348.66 | |
88104.83 | 18355.76 | 24 | 59199.16 | |
90747.97 | 18906.43 | 23 | 58071.56 | |
93470.41 | 19473.63 | 22 | 56965.43 | |
96274.53 | 20057.83 | 21 | 55880.38 | |
99162.76 | 20659.57 | 20 | 54815.99 | |
102137.64 | 21279.36 | 19 | 53771.88 | |
105201.77 | 21917.74 | 18 | 52747.65 | |
108357.83 | 22575.27 | 17 | 51742.93 | |
111608.56 | 23252.53 | 16 | 50757.35 | |
114956.82 | 23950.10 | 15 | 49790.55 | |
118405.52 | 24668.61 | 14 | 48842.15 | |
121957.69 | 25408.67 | 13 | 47911.83 | |
125616.42 | 26170.92 | 12 | 46999.22 | |
129384.91 | 26956.05 | 11 | 46104.00 | |
133266.46 | 27764.73 | 10 | 45225.83 | |
137264.45 | 28597.68 | 9 | 44364.38 | |
141382.39 | 29455.61 | 8 | 43519.35 | |
145623.86 | 30339.27 | 7 | 42690.41 | |
149992.57 | 31249.45 | 6 | 41877.26 | |
154492.35 | 32186.94 | 5 | 41079.59 | |
159127.12 | 33152.54 | 4 | 40297.13 | |
163900.94 | 34147.12 | 3 | 39529.56 | |
168817.96 | 35171.53 | 2 | 38776.62 | |
173882.50 | 36226.68 | 1 | 38038.01 | |
179098.98 | 37313.48 | 0 | 37313.48 | |
TOTAL | 753301.52 | 1500002.92 | ||
Principal | 753301.52 | |||
Amount at end of 30 years | 1500002.92 | |||
Total Return (A-P) | 746701.4023 |
Therefore, 20.834 % percentage of his salary he should put in the investment annually to get an amount equal to 1500000 at the end of 30 years.
To get an interest equal to 1500000, then 41.852% should be invested.
Amount = Principal (1+r)^t | ||||
Year 1 | Investment in Retirement account(41.852% of Salary) (P) | Years left(t) | Amount | |
76000.00 | 31807.52 | 29 | 130924.07 | |
78280.00 | 32761.75 | 28 | 128430.27 | |
80628.40 | 33744.60 | 27 | 125983.98 | |
83047.25 | 34756.94 | 26 | 123584.29 | |
85538.67 | 35799.64 | 25 | 121230.30 | |
88104.83 | 36873.63 | 24 | 118921.15 | |
90747.97 | 37979.84 | 23 | 116655.99 | |
93470.41 | 39119.24 | 22 | 114433.97 | |
96274.53 | 40292.81 | 21 | 112254.27 | |
99162.76 | 41501.60 | 20 | 110116.10 | |
102137.64 | 42746.65 | 19 | 108018.65 | |
105201.77 | 44029.05 | 18 | 105961.15 | |
108357.83 | 45349.92 | 17 | 103942.84 | |
111608.56 | 46710.42 | 16 | 101962.98 | |
114956.82 | 48111.73 | 15 | 100020.83 | |
118405.52 | 49555.08 | 14 | 98115.67 | |
121957.69 | 51041.73 | 13 | 96246.80 | |
125616.42 | 52572.98 | 12 | 94413.53 | |
129384.91 | 54150.17 | 11 | 92615.17 | |
133266.46 | 55774.68 | 10 | 90851.07 | |
137264.45 | 57447.92 | 9 | 89120.58 | |
141382.39 | 59171.36 | 8 | 87423.04 | |
145623.86 | 60946.50 | 7 | 85757.84 | |
149992.57 | 62774.89 | 6 | 84124.36 | |
154492.35 | 64658.14 | 5 | 82521.99 | |
159127.12 | 66597.88 | 4 | 80950.14 | |
163900.94 | 68595.82 | 3 | 79408.24 | |
168817.96 | 70653.69 | 2 | 77895.70 | |
173882.50 | 72773.31 | 1 | 76411.97 | |
179098.98 | 74956.50 | 0 | 74956.50 | |
TOTAL | 1513255.99 | 3013253.45 | ||
Principal | 1513255.99 | |||
Amount at end of 30 years | 3013253.45 | |||
Total Return (A-P) | 1499997.46 | |||
Gain of 1500000 can be taken in both ways i.e. Total Amount as 1500000 or just the interest component of it.