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jhannah/gist:4c74c240ba987edea6e5f0f72a342ab3

Created December 16, 2021 20:42
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Amortization schedule w/ principle-only payments
Raw
gistfile1.txt
Here's a little Perl script I wrote:
https://github.com/jhannah/sandbox/blob/main/amortize.pl
✗ ./amortize.pl
Usage:
amortize.pl --principle=176000 --periods=180 --interest_rate=2.13 \
--principle_payment=12:2000 \
--principle_payment=24:2000
Take out a $176,000 loan over 15 years at 2.13% APR.
But make a $2,000 principle-only payment after payment #12.
And another after payment #24.
Those extra payments shorten the number of payments we have to make,
and make the last payment smaller.
✗ ./amortize.pl --principle=176000 --periods=180 --interest_rate=2.13 \
--principle_payment=12:2000 \
--principle_payment=24:2000
# Payment Int Princ Balance
--- -------- ------ -------- ----------
1 1,143.14 312.40 830.74 175,169.26
2 1,143.14 310.93 832.22 174,337.04
3 1,143.14 309.45 833.69 173,503.35
4 1,143.14 307.97 835.17 172,668.18
5 1,143.14 306.49 836.66 171,831.52
6 1,143.14 305.00 838.14 170,993.38
7 1,143.14 303.51 839.63 170,153.75
8 1,143.14 302.02 841.12 169,312.63
9 1,143.14 300.53 842.61 168,470.02
10 1,143.14 299.03 844.11 167,625.91
11 1,143.14 297.54 845.61 166,780.31
12 1,143.14 296.04 847.11 165,933.20
Principle-only payment made:
2,000.00 163,933.20
13 1,143.14 290.98 852.16 163,081.04
14 1,143.14 289.47 853.67 162,227.37
15 1,143.14 287.95 855.19 161,372.18
16 1,143.14 286.44 856.71 160,515.48
17 1,143.14 284.91 858.23 159,657.25
18 1,143.14 283.39 859.75 158,797.50
19 1,143.14 281.87 861.28 157,936.22
20 1,143.14 280.34 862.80 157,073.42
21 1,143.14 278.81 864.34 156,209.08
22 1,143.14 277.27 865.87 155,343.21
23 1,143.14 275.73 867.41 154,475.81
24 1,143.14 274.19 868.95 153,606.86
Principle-only payment made:
2,000.00 151,606.86
25 1,143.14 269.10 874.04 150,732.82
26 1,143.14 267.55 875.59 149,857.23
27 1,143.14 266.00 877.14 148,980.08
28 1,143.14 264.44 878.70 148,101.38
29 1,143.14 262.88 880.26 147,221.12
30 1,143.14 261.32 881.82 146,339.30
31 1,143.14 259.75 883.39 145,455.91
32 1,143.14 258.18 884.96 144,570.95
33 1,143.14 256.61 886.53 143,684.42
34 1,143.14 255.04 888.10 142,796.32
35 1,143.14 253.46 889.68 141,906.64
36 1,143.14 251.88 891.26 141,015.38
37 1,143.14 250.30 892.84 140,122.55
38 1,143.14 248.72 894.42 139,228.12
39 1,143.14 247.13 896.01 138,332.11
40 1,143.14 245.54 897.60 137,434.51
41 1,143.14 243.95 899.20 136,535.31
42 1,143.14 242.35 900.79 135,634.52
43 1,143.14 240.75 902.39 134,732.13
44 1,143.14 239.15 903.99 133,828.14
45 1,143.14 237.54 905.60 132,922.54
46 1,143.14 235.94 907.20 132,015.34
47 1,143.14 234.33 908.81 131,106.52
48 1,143.14 232.71 910.43 130,196.10
49 1,143.14 231.10 912.04 129,284.05
50 1,143.14 229.48 913.66 128,370.39
51 1,143.14 227.86 915.28 127,455.11
52 1,143.14 226.23 916.91 126,538.20
53 1,143.14 224.61 918.54 125,619.66
54 1,143.14 222.97 920.17 124,699.50
55 1,143.14 221.34 921.80 123,777.70
56 1,143.14 219.71 923.44 122,854.26
57 1,143.14 218.07 925.08 121,929.18
58 1,143.14 216.42 926.72 121,002.47
59 1,143.14 214.78 928.36 120,074.10
60 1,143.14 213.13 930.01 119,144.09
61 1,143.14 211.48 931.66 118,212.43
62 1,143.14 209.83 933.31 117,279.12
63 1,143.14 208.17 934.97 116,344.15
64 1,143.14 206.51 936.63 115,407.52
65 1,143.14 204.85 938.29 114,469.22
66 1,143.14 203.18 939.96 113,529.27
67 1,143.14 201.51 941.63 112,587.64
68 1,143.14 199.84 943.30 111,644.34
69 1,143.14 198.17 944.97 110,699.37
70 1,143.14 196.49 946.65 109,752.72
71 1,143.14 194.81 948.33 108,804.39
72 1,143.14 193.13 950.01 107,854.37
73 1,143.14 191.44 951.70 106,902.67
74 1,143.14 189.75 953.39 105,949.28
75 1,143.14 188.06 955.08 104,994.20
76 1,143.14 186.36 956.78 104,037.43
77 1,143.14 184.67 958.48 103,078.95
78 1,143.14 182.97 960.18 102,118.77
79 1,143.14 181.26 961.88 101,156.89
80 1,143.14 179.55 963.59 100,193.31
81 1,143.14 177.84 965.30 99,228.01
82 1,143.14 176.13 967.01 98,261.00
83 1,143.14 174.41 968.73 97,292.27
84 1,143.14 172.69 970.45 96,321.82
85 1,143.14 170.97 972.17 95,349.65
86 1,143.14 169.25 973.90 94,375.75
87 1,143.14 167.52 975.62 93,400.13
88 1,143.14 165.79 977.36 92,422.77
89 1,143.14 164.05 979.09 91,443.68
90 1,143.14 162.31 980.83 90,462.85
91 1,143.14 160.57 982.57 89,480.28
92 1,143.14 158.83 984.31 88,495.97
93 1,143.14 157.08 986.06 87,509.91
94 1,143.14 155.33 987.81 86,522.10
95 1,143.14 153.58 989.56 85,532.53
96 1,143.14 151.82 991.32 84,541.21
97 1,143.14 150.06 993.08 83,548.13
98 1,143.14 148.30 994.84 82,553.29
99 1,143.14 146.53 996.61 81,556.68
100 1,143.14 144.76 998.38 80,558.30
101 1,143.14 142.99 1,000.15 79,558.15
102 1,143.14 141.22 1,001.93 78,556.22
103 1,143.14 139.44 1,003.70 77,552.52
104 1,143.14 137.66 1,005.49 76,547.03
105 1,143.14 135.87 1,007.27 75,539.76
106 1,143.14 134.08 1,009.06 74,530.70
107 1,143.14 132.29 1,010.85 73,519.85
108 1,143.14 130.50 1,012.64 72,507.21
109 1,143.14 128.70 1,014.44 71,492.77
110 1,143.14 126.90 1,016.24 70,476.53
111 1,143.14 125.10 1,018.05 69,458.48
112 1,143.14 123.29 1,019.85 68,438.63
113 1,143.14 121.48 1,021.66 67,416.97
114 1,143.14 119.67 1,023.48 66,393.49
115 1,143.14 117.85 1,025.29 65,368.20
116 1,143.14 116.03 1,027.11 64,341.08
117 1,143.14 114.21 1,028.94 63,312.15
118 1,143.14 112.38 1,030.76 62,281.38
119 1,143.14 110.55 1,032.59 61,248.79
120 1,143.14 108.72 1,034.42 60,214.37
121 1,143.14 106.88 1,036.26 59,178.11
122 1,143.14 105.04 1,038.10 58,140.01
123 1,143.14 103.20 1,039.94 57,100.06
124 1,143.14 101.35 1,041.79 56,058.27
125 1,143.14 99.50 1,043.64 55,014.64
126 1,143.14 97.65 1,045.49 53,969.15
127 1,143.14 95.80 1,047.35 52,921.80
128 1,143.14 93.94 1,049.21 51,872.59
129 1,143.14 92.07 1,051.07 50,821.53
130 1,143.14 90.21 1,052.93 49,768.59
131 1,143.14 88.34 1,054.80 48,713.79
132 1,143.14 86.47 1,056.67 47,657.12
133 1,143.14 84.59 1,058.55 46,598.57
134 1,143.14 82.71 1,060.43 45,538.14
135 1,143.14 80.83 1,062.31 44,475.83
136 1,143.14 78.94 1,064.20 43,411.63
137 1,143.14 77.06 1,066.09 42,345.54
138 1,143.14 75.16 1,067.98 41,277.57
139 1,143.14 73.27 1,069.87 40,207.69
140 1,143.14 71.37 1,071.77 39,135.92
141 1,143.14 69.47 1,073.68 38,062.24
142 1,143.14 67.56 1,075.58 36,986.66
143 1,143.14 65.65 1,077.49 35,909.17
144 1,143.14 63.74 1,079.40 34,829.77
145 1,143.14 61.82 1,081.32 33,748.45
146 1,143.14 59.90 1,083.24 32,665.21
147 1,143.14 57.98 1,085.16 31,580.05
148 1,143.14 56.05 1,087.09 30,492.97
149 1,143.14 54.13 1,089.02 29,403.95
150 1,143.14 52.19 1,090.95 28,313.00
151 1,143.14 50.26 1,092.89 27,220.11
152 1,143.14 48.32 1,094.83 26,125.29
153 1,143.14 46.37 1,096.77 25,028.52
154 1,143.14 44.43 1,098.72 23,929.80
155 1,143.14 42.48 1,100.67 22,829.14
156 1,143.14 40.52 1,102.62 21,726.52
157 1,143.14 38.56 1,104.58 20,621.94
158 1,143.14 36.60 1,106.54 19,515.40
159 1,143.14 34.64 1,108.50 18,406.90
160 1,143.14 32.67 1,110.47 17,296.43
161 1,143.14 30.70 1,112.44 16,183.99
162 1,143.14 28.73 1,114.41 15,069.58
163 1,143.14 26.75 1,116.39 13,953.18
164 1,143.14 24.77 1,118.37 12,834.81
165 1,143.14 22.78 1,120.36 11,714.45
166 1,143.14 20.79 1,122.35 10,592.10
167 1,143.14 18.80 1,124.34 9,467.76
168 1,143.14 16.81 1,126.34 8,341.42
169 1,143.14 14.81 1,128.34 7,213.09
170 1,143.14 12.80 1,130.34 6,082.75
171 1,143.14 10.80 1,132.34 4,950.41
172 1,143.14 8.79 1,134.35 3,816.05
173 1,143.14 6.77 1,136.37 2,679.68
174 1,143.14 4.76 1,138.39 1,541.30
175 1,143.14 2.74 1,140.41 400.89
176 401.60 0.71 400.89 0.00
Total interest paid: 28,451.37
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