Mortgage prepayment calculator

Compare a dated prepayment plan with the same mortgage paid without extra amounts.

Mortgage balance

Nominal annual interest rate

Amortization (whole months)

Nominal rate compounding

Payment frequency

First scheduled payment

Extra amount each payment

Begin extra payments

One-time lump sum

Lump sum on or after this date

Annual increase in regular payment

Regular payment before extras: $2,326.42
Interest with prepayments: $261,846.64
Interest saved: $36,079.34
Payments with prepayments: 271
Payments without prepayments: 300
Years saved: 2.4167
Final payment: $1,713.26
Prepayment plan payoff date: 2049-05-01
Baseline payoff date: 2051-10-01

Estimates for information only. Not financial, medical, legal or engineering advice. See the Terms.

Prepayment amortization schedule
Payment	Due date	Amount ($)	Interest ($)	Principal ($)	Balance ($)
1.00	2026-11-01	2,426.42	1,649.57	776.85	399,223.15
2.00	2026-12-01	2,426.42	1,646.36	780.06	398,443.09
3.00	2027-01-01	2,426.42	1,643.15	783.27	397,659.81
4.00	2027-02-01	2,426.42	1,639.92	786.50	396,873.31
5.00	2027-03-01	2,426.42	1,636.67	789.75	396,083.56
6.00	2027-04-01	2,426.42	1,633.42	793.00	395,290.56
7.00	2027-05-01	2,426.42	1,630.14	796.28	394,494.28
8.00	2027-06-01	2,426.42	1,626.86	799.56	393,694.72
9.00	2027-07-01	2,426.42	1,623.56	802.86	392,891.87
10.00	2027-08-01	2,426.42	1,620.25	806.17	392,085.70
11.00	2027-09-01	2,426.42	1,616.93	809.49	391,276.21
12.00	2027-10-01	2,426.42	1,613.59	812.83	390,463.38
13.00	2027-11-01	7,426.42	1,610.24	5,816.18	384,647.20
14.00	2027-12-01	2,426.42	1,586.25	840.17	383,807.03
15.00	2028-01-01	2,426.42	1,582.79	843.63	382,963.40
16.00	2028-02-01	2,426.42	1,579.31	847.11	382,116.29
17.00	2028-03-01	2,426.42	1,575.82	850.60	381,265.68
18.00	2028-04-01	2,426.42	1,572.31	854.11	380,411.57
19.00	2028-05-01	2,426.42	1,568.79	857.63	379,553.93
20.00	2028-06-01	2,426.42	1,565.25	861.17	378,692.76
21.00	2028-07-01	2,426.42	1,561.70	864.72	377,828.04
22.00	2028-08-01	2,426.42	1,558.13	868.29	376,959.75
23.00	2028-09-01	2,426.42	1,554.55	871.87	376,087.88
24.00	2028-10-01	2,426.42	1,550.95	875.47	375,212.41
25.00	2028-11-01	2,426.42	1,547.34	879.08	374,333.34
26.00	2028-12-01	2,426.42	1,543.72	882.70	373,450.64
27.00	2029-01-01	2,426.42	1,540.08	886.34	372,564.30
28.00	2029-02-01	2,426.42	1,536.42	890.00	371,674.30
29.00	2029-03-01	2,426.42	1,532.75	893.67	370,780.63
30.00	2029-04-01	2,426.42	1,529.07	897.35	369,883.28
31.00	2029-05-01	2,426.42	1,525.37	901.05	368,982.23
32.00	2029-06-01	2,426.42	1,521.65	904.77	368,077.46
33.00	2029-07-01	2,426.42	1,517.92	908.50	367,168.96
34.00	2029-08-01	2,426.42	1,514.17	912.25	366,256.72
35.00	2029-09-01	2,426.42	1,510.41	916.01	365,340.71
36.00	2029-10-01	2,426.42	1,506.63	919.79	364,420.92
37.00	2029-11-01	2,426.42	1,502.84	923.58	363,497.34
38.00	2029-12-01	2,426.42	1,499.03	927.39	362,569.96
39.00	2030-01-01	2,426.42	1,495.21	931.21	361,638.74
40.00	2030-02-01	2,426.42	1,491.37	935.05	360,703.69
41.00	2030-03-01	2,426.42	1,487.51	938.91	359,764.78
42.00	2030-04-01	2,426.42	1,483.64	942.78	358,822.00
43.00	2030-05-01	2,426.42	1,479.75	946.67	357,875.33
44.00	2030-06-01	2,426.42	1,475.85	950.57	356,924.76
45.00	2030-07-01	2,426.42	1,471.93	954.49	355,970.27
46.00	2030-08-01	2,426.42	1,467.99	958.43	355,011.84
47.00	2030-09-01	2,426.42	1,464.04	962.38	354,049.46
48.00	2030-10-01	2,426.42	1,460.07	966.35	353,083.11
49.00	2030-11-01	2,426.42	1,456.08	970.34	352,112.77
50.00	2030-12-01	2,426.42	1,452.08	974.34	351,138.44
51.00	2031-01-01	2,426.42	1,448.07	978.35	350,160.08
52.00	2031-02-01	2,426.42	1,444.03	982.39	349,177.69
53.00	2031-03-01	2,426.42	1,439.98	986.44	348,191.25
54.00	2031-04-01	2,426.42	1,435.91	990.51	347,200.74
55.00	2031-05-01	2,426.42	1,431.83	994.59	346,206.15
56.00	2031-06-01	2,426.42	1,427.72	998.70	345,207.46
57.00	2031-07-01	2,426.42	1,423.61	1,002.81	344,204.64
58.00	2031-08-01	2,426.42	1,419.47	1,006.95	343,197.69
59.00	2031-09-01	2,426.42	1,415.32	1,011.10	342,186.59
60.00	2031-10-01	2,426.42	1,411.15	1,015.27	341,171.32
61.00	2031-11-01	2,426.42	1,406.96	1,019.46	340,151.86
62.00	2031-12-01	2,426.42	1,402.76	1,023.66	339,128.20
63.00	2032-01-01	2,426.42	1,398.54	1,027.88	338,100.32
64.00	2032-02-01	2,426.42	1,394.30	1,032.12	337,068.19
65.00	2032-03-01	2,426.42	1,390.04	1,036.38	336,031.81
66.00	2032-04-01	2,426.42	1,385.77	1,040.65	334,991.16
67.00	2032-05-01	2,426.42	1,381.48	1,044.94	333,946.22
68.00	2032-06-01	2,426.42	1,377.17	1,049.25	332,896.96
69.00	2032-07-01	2,426.42	1,372.84	1,053.58	331,843.38
70.00	2032-08-01	2,426.42	1,368.49	1,057.93	330,785.45
71.00	2032-09-01	2,426.42	1,364.13	1,062.29	329,723.17
72.00	2032-10-01	2,426.42	1,359.75	1,066.67	328,656.50
73.00	2032-11-01	2,426.42	1,355.35	1,071.07	327,585.43
74.00	2032-12-01	2,426.42	1,350.93	1,075.49	326,509.94
75.00	2033-01-01	2,426.42	1,346.50	1,079.92	325,430.02
76.00	2033-02-01	2,426.42	1,342.05	1,084.37	324,345.65
77.00	2033-03-01	2,426.42	1,337.57	1,088.85	323,256.80
78.00	2033-04-01	2,426.42	1,333.08	1,093.34	322,163.47
79.00	2033-05-01	2,426.42	1,328.57	1,097.85	321,065.62
80.00	2033-06-01	2,426.42	1,324.05	1,102.37	319,963.25
81.00	2033-07-01	2,426.42	1,319.50	1,106.92	318,856.33
82.00	2033-08-01	2,426.42	1,314.94	1,111.48	317,744.85
83.00	2033-09-01	2,426.42	1,310.35	1,116.07	316,628.78
84.00	2033-10-01	2,426.42	1,305.75	1,120.67	315,508.11
85.00	2033-11-01	2,426.42	1,301.13	1,125.29	314,382.82
86.00	2033-12-01	2,426.42	1,296.49	1,129.93	313,252.89
87.00	2034-01-01	2,426.42	1,291.83	1,134.59	312,118.30
88.00	2034-02-01	2,426.42	1,287.15	1,139.27	310,979.03
89.00	2034-03-01	2,426.42	1,282.45	1,143.97	309,835.06
90.00	2034-04-01	2,426.42	1,277.73	1,148.69	308,686.37
91.00	2034-05-01	2,426.42	1,273.00	1,153.42	307,532.95
92.00	2034-06-01	2,426.42	1,268.24	1,158.18	306,374.77
93.00	2034-07-01	2,426.42	1,263.46	1,162.96	305,211.81
94.00	2034-08-01	2,426.42	1,258.67	1,167.75	304,044.06
95.00	2034-09-01	2,426.42	1,253.85	1,172.57	302,871.49
96.00	2034-10-01	2,426.42	1,249.02	1,177.40	301,694.09
97.00	2034-11-01	2,426.42	1,244.16	1,182.26	300,511.83
98.00	2034-12-01	2,426.42	1,239.29	1,187.13	299,324.69
99.00	2035-01-01	2,426.42	1,234.39	1,192.03	298,132.66
100.00	2035-02-01	2,426.42	1,229.47	1,196.95	296,935.72
101.00	2035-03-01	2,426.42	1,224.54	1,201.88	295,733.83
102.00	2035-04-01	2,426.42	1,219.58	1,206.84	294,527.00
103.00	2035-05-01	2,426.42	1,214.60	1,211.82	293,315.18
104.00	2035-06-01	2,426.42	1,209.61	1,216.81	292,098.37
105.00	2035-07-01	2,426.42	1,204.59	1,221.83	290,876.54
106.00	2035-08-01	2,426.42	1,199.55	1,226.87	289,649.67
107.00	2035-09-01	2,426.42	1,194.49	1,231.93	288,417.74
108.00	2035-10-01	2,426.42	1,189.41	1,237.01	287,180.73
109.00	2035-11-01	2,426.42	1,184.31	1,242.11	285,938.62
110.00	2035-12-01	2,426.42	1,179.19	1,247.23	284,691.38
111.00	2036-01-01	2,426.42	1,174.04	1,252.38	283,439.01
112.00	2036-02-01	2,426.42	1,168.88	1,257.54	282,181.47
113.00	2036-03-01	2,426.42	1,163.69	1,262.73	280,918.74
114.00	2036-04-01	2,426.42	1,158.49	1,267.93	279,650.80
115.00	2036-05-01	2,426.42	1,153.26	1,273.16	278,377.64
116.00	2036-06-01	2,426.42	1,148.01	1,278.41	277,099.23
117.00	2036-07-01	2,426.42	1,142.73	1,283.69	275,815.54
118.00	2036-08-01	2,426.42	1,137.44	1,288.98	274,526.56
119.00	2036-09-01	2,426.42	1,132.12	1,294.30	273,232.26
120.00	2036-10-01	2,426.42	1,126.79	1,299.63	271,932.63
121.00	2036-11-01	2,426.42	1,121.43	1,304.99	270,627.64
122.00	2036-12-01	2,426.42	1,116.05	1,310.37	269,317.26
123.00	2037-01-01	2,426.42	1,110.64	1,315.78	268,001.49
124.00	2037-02-01	2,426.42	1,105.22	1,321.20	266,680.28
125.00	2037-03-01	2,426.42	1,099.77	1,326.65	265,353.63
126.00	2037-04-01	2,426.42	1,094.30	1,332.12	264,021.50
127.00	2037-05-01	2,426.42	1,088.80	1,337.62	262,683.89
128.00	2037-06-01	2,426.42	1,083.29	1,343.13	261,340.75
129.00	2037-07-01	2,426.42	1,077.75	1,348.67	259,992.08
130.00	2037-08-01	2,426.42	1,072.19	1,354.23	258,637.85
131.00	2037-09-01	2,426.42	1,066.60	1,359.82	257,278.03
132.00	2037-10-01	2,426.42	1,060.99	1,365.43	255,912.60
133.00	2037-11-01	2,426.42	1,055.36	1,371.06	254,541.54
134.00	2037-12-01	2,426.42	1,049.71	1,376.71	253,164.83
135.00	2038-01-01	2,426.42	1,044.03	1,382.39	251,782.44
136.00	2038-02-01	2,426.42	1,038.33	1,388.09	250,394.35
137.00	2038-03-01	2,426.42	1,032.61	1,393.81	249,000.53
138.00	2038-04-01	2,426.42	1,026.86	1,399.56	247,600.97
139.00	2038-05-01	2,426.42	1,021.09	1,405.33	246,195.64
140.00	2038-06-01	2,426.42	1,015.29	1,411.13	244,784.51
141.00	2038-07-01	2,426.42	1,009.47	1,416.95	243,367.56
142.00	2038-08-01	2,426.42	1,003.63	1,422.79	241,944.76
143.00	2038-09-01	2,426.42	997.76	1,428.66	240,516.10
144.00	2038-10-01	2,426.42	991.87	1,434.55	239,081.55
145.00	2038-11-01	2,426.42	985.95	1,440.47	237,641.08
146.00	2038-12-01	2,426.42	980.01	1,446.41	236,194.68
147.00	2039-01-01	2,426.42	974.05	1,452.37	234,742.30
148.00	2039-02-01	2,426.42	968.06	1,458.36	233,283.94
149.00	2039-03-01	2,426.42	962.04	1,464.38	231,819.56
150.00	2039-04-01	2,426.42	956.00	1,470.42	230,349.15
151.00	2039-05-01	2,426.42	949.94	1,476.48	228,872.67
152.00	2039-06-01	2,426.42	943.85	1,482.57	227,390.10
153.00	2039-07-01	2,426.42	937.74	1,488.68	225,901.42
154.00	2039-08-01	2,426.42	931.60	1,494.82	224,406.60
155.00	2039-09-01	2,426.42	925.43	1,500.99	222,905.61
156.00	2039-10-01	2,426.42	919.24	1,507.18	221,398.43
157.00	2039-11-01	2,426.42	913.03	1,513.39	219,885.04
158.00	2039-12-01	2,426.42	906.79	1,519.63	218,365.41
159.00	2040-01-01	2,426.42	900.52	1,525.90	216,839.51
160.00	2040-02-01	2,426.42	894.23	1,532.19	215,307.32
161.00	2040-03-01	2,426.42	887.91	1,538.51	213,768.81
162.00	2040-04-01	2,426.42	881.56	1,544.86	212,223.95
163.00	2040-05-01	2,426.42	875.19	1,551.23	210,672.73
164.00	2040-06-01	2,426.42	868.80	1,557.62	209,115.10
165.00	2040-07-01	2,426.42	862.37	1,564.05	207,551.06
166.00	2040-08-01	2,426.42	855.92	1,570.50	205,980.56
167.00	2040-09-01	2,426.42	849.45	1,576.97	204,403.59
168.00	2040-10-01	2,426.42	842.94	1,583.48	202,820.11
169.00	2040-11-01	2,426.42	836.41	1,590.01	201,230.10
170.00	2040-12-01	2,426.42	829.86	1,596.56	199,633.54
171.00	2041-01-01	2,426.42	823.27	1,603.15	198,030.39
172.00	2041-02-01	2,426.42	816.66	1,609.76	196,420.63
173.00	2041-03-01	2,426.42	810.02	1,616.40	194,804.23
174.00	2041-04-01	2,426.42	803.36	1,623.06	193,181.17
175.00	2041-05-01	2,426.42	796.66	1,629.76	191,551.41
176.00	2041-06-01	2,426.42	789.94	1,636.48	189,914.93
177.00	2041-07-01	2,426.42	783.19	1,643.23	188,271.71
178.00	2041-08-01	2,426.42	776.42	1,650.00	186,621.70
179.00	2041-09-01	2,426.42	769.61	1,656.81	184,964.90
180.00	2041-10-01	2,426.42	762.78	1,663.64	183,301.25
181.00	2041-11-01	2,426.42	755.92	1,670.50	181,630.75
182.00	2041-12-01	2,426.42	749.03	1,677.39	179,953.36
183.00	2042-01-01	2,426.42	742.11	1,684.31	178,269.06
184.00	2042-02-01	2,426.42	735.17	1,691.25	176,577.80
185.00	2042-03-01	2,426.42	728.19	1,698.23	174,879.57
186.00	2042-04-01	2,426.42	721.19	1,705.23	173,174.34
187.00	2042-05-01	2,426.42	714.16	1,712.26	171,462.08
188.00	2042-06-01	2,426.42	707.10	1,719.32	169,742.76
189.00	2042-07-01	2,426.42	700.00	1,726.42	168,016.34
190.00	2042-08-01	2,426.42	692.89	1,733.53	166,282.81
191.00	2042-09-01	2,426.42	685.74	1,740.68	164,542.12
192.00	2042-10-01	2,426.42	678.56	1,747.86	162,794.26
193.00	2042-11-01	2,426.42	671.35	1,755.07	161,039.19
194.00	2042-12-01	2,426.42	664.11	1,762.31	159,276.88
195.00	2043-01-01	2,426.42	656.84	1,769.58	157,507.31
196.00	2043-02-01	2,426.42	649.55	1,776.87	155,730.43
197.00	2043-03-01	2,426.42	642.22	1,784.20	153,946.23
198.00	2043-04-01	2,426.42	634.86	1,791.56	152,154.67
199.00	2043-05-01	2,426.42	627.47	1,798.95	150,355.73
200.00	2043-06-01	2,426.42	620.05	1,806.37	148,549.36
201.00	2043-07-01	2,426.42	612.61	1,813.81	146,735.55
202.00	2043-08-01	2,426.42	605.12	1,821.29	144,914.25
203.00	2043-09-01	2,426.42	597.61	1,828.81	143,085.44
204.00	2043-10-01	2,426.42	590.07	1,836.35	141,249.10
205.00	2043-11-01	2,426.42	582.50	1,843.92	139,405.18
206.00	2043-12-01	2,426.42	574.90	1,851.52	137,553.65
207.00	2044-01-01	2,426.42	567.26	1,859.16	135,694.49
208.00	2044-02-01	2,426.42	559.59	1,866.83	133,827.66
209.00	2044-03-01	2,426.42	551.89	1,874.53	131,953.14
210.00	2044-04-01	2,426.42	544.16	1,882.26	130,070.88
211.00	2044-05-01	2,426.42	536.40	1,890.02	128,180.86
212.00	2044-06-01	2,426.42	528.61	1,897.81	126,283.05
213.00	2044-07-01	2,426.42	520.78	1,905.64	124,377.41
214.00	2044-08-01	2,426.42	512.92	1,913.50	122,463.91
215.00	2044-09-01	2,426.42	505.03	1,921.39	120,542.52
216.00	2044-10-01	2,426.42	497.11	1,929.31	118,613.21
217.00	2044-11-01	2,426.42	489.15	1,937.27	116,675.94
218.00	2044-12-01	2,426.42	481.16	1,945.26	114,730.68
219.00	2045-01-01	2,426.42	473.14	1,953.28	112,777.40
220.00	2045-02-01	2,426.42	465.08	1,961.34	110,816.07
221.00	2045-03-01	2,426.42	457.00	1,969.42	108,846.64
222.00	2045-04-01	2,426.42	448.87	1,977.55	106,869.10
223.00	2045-05-01	2,426.42	440.72	1,985.70	104,883.40
224.00	2045-06-01	2,426.42	432.53	1,993.89	102,889.51
225.00	2045-07-01	2,426.42	424.31	2,002.11	100,887.40
226.00	2045-08-01	2,426.42	416.05	2,010.37	98,877.03
227.00	2045-09-01	2,426.42	407.76	2,018.66	96,858.37
228.00	2045-10-01	2,426.42	399.44	2,026.98	94,831.38
229.00	2045-11-01	2,426.42	391.08	2,035.34	92,796.04
230.00	2045-12-01	2,426.42	382.68	2,043.74	90,752.30
231.00	2046-01-01	2,426.42	374.25	2,052.17	88,700.14
232.00	2046-02-01	2,426.42	365.79	2,060.63	86,639.51
233.00	2046-03-01	2,426.42	357.29	2,069.13	84,570.38
234.00	2046-04-01	2,426.42	348.76	2,077.66	82,492.73
235.00	2046-05-01	2,426.42	340.19	2,086.23	80,406.50
236.00	2046-06-01	2,426.42	331.59	2,094.83	78,311.67
237.00	2046-07-01	2,426.42	322.95	2,103.47	76,208.20
238.00	2046-08-01	2,426.42	314.28	2,112.14	74,096.05
239.00	2046-09-01	2,426.42	305.57	2,120.85	71,975.20
240.00	2046-10-01	2,426.42	296.82	2,129.60	69,845.60
241.00	2046-11-01	2,426.42	288.04	2,138.38	67,707.22
242.00	2046-12-01	2,426.42	279.22	2,147.20	65,560.02
243.00	2047-01-01	2,426.42	270.36	2,156.06	63,403.96
244.00	2047-02-01	2,426.42	261.47	2,164.95	61,239.01
245.00	2047-03-01	2,426.42	252.54	2,173.88	59,065.14
246.00	2047-04-01	2,426.42	243.58	2,182.84	56,882.30
247.00	2047-05-01	2,426.42	234.58	2,191.84	54,690.46
248.00	2047-06-01	2,426.42	225.54	2,200.88	52,489.57
249.00	2047-07-01	2,426.42	216.46	2,209.96	50,279.62
250.00	2047-08-01	2,426.42	207.35	2,219.07	48,060.55
251.00	2047-09-01	2,426.42	198.20	2,228.22	45,832.32
252.00	2047-10-01	2,426.42	189.01	2,237.41	43,594.91
253.00	2047-11-01	2,426.42	179.78	2,246.64	41,348.27
254.00	2047-12-01	2,426.42	170.52	2,255.90	39,092.37
255.00	2048-01-01	2,426.42	161.21	2,265.21	36,827.16
256.00	2048-02-01	2,426.42	151.87	2,274.55	34,552.62
257.00	2048-03-01	2,426.42	142.49	2,283.93	32,268.69
258.00	2048-04-01	2,426.42	133.07	2,293.35	29,975.34
259.00	2048-05-01	2,426.42	123.62	2,302.80	27,672.54
260.00	2048-06-01	2,426.42	114.12	2,312.30	25,360.24
261.00	2048-07-01	2,426.42	104.58	2,321.84	23,038.40
262.00	2048-08-01	2,426.42	95.01	2,331.41	20,706.99
263.00	2048-09-01	2,426.42	85.39	2,341.03	18,365.96
264.00	2048-10-01	2,426.42	75.74	2,350.68	16,015.28
265.00	2048-11-01	2,426.42	66.05	2,360.37	13,654.91
266.00	2048-12-01	2,426.42	56.31	2,370.11	11,284.80
267.00	2049-01-01	2,426.42	46.54	2,379.88	8,904.92
268.00	2049-02-01	2,426.42	36.72	2,389.70	6,515.22
269.00	2049-03-01	2,426.42	26.87	2,399.55	4,115.67
270.00	2049-04-01	2,426.42	16.97	2,409.45	1,706.22
271.00	2049-05-01	1,713.26	7.04	1,706.22	0.00

Annual payment breakdown
Payment year	Paid ($)	Interest ($)	Principal ($)	Closing balance ($)
1.00	29,117.04	19,580.42	9,536.62	390,463.38
2.00	34,117.04	18,866.08	15,250.96	375,212.41
3.00	29,117.04	18,325.55	10,791.49	364,420.92
4.00	29,117.04	17,779.23	11,337.81	353,083.11
5.00	29,117.04	17,205.25	11,911.79	341,171.32
6.00	29,117.04	16,602.22	12,514.82	328,656.50
7.00	29,117.04	15,968.65	13,148.39	315,508.11
8.00	29,117.04	15,303.02	13,814.02	301,694.09
9.00	29,117.04	14,603.68	14,513.36	287,180.73
10.00	29,117.04	13,868.94	15,248.10	271,932.63
11.00	29,117.04	13,097.01	16,020.03	255,912.60
12.00	29,117.04	12,285.99	16,831.05	239,081.55
13.00	29,117.04	11,433.92	17,683.12	221,398.43
14.00	29,117.04	10,538.71	18,578.33	202,820.11
15.00	29,117.04	9,598.19	19,518.85	183,301.25
16.00	29,117.04	8,610.04	20,507.00	162,794.26
17.00	29,117.04	7,571.88	21,545.16	141,249.10
18.00	29,117.04	6,481.15	22,635.89	118,613.21
19.00	29,117.04	5,335.21	23,781.83	94,831.38
20.00	29,117.04	4,131.26	24,985.78	69,845.60
21.00	29,117.04	2,866.35	26,250.69	43,594.91
22.00	29,117.04	1,537.41	27,579.63	16,015.28
23.00	16,271.78	256.50	16,015.28	0.00

How this calculator works

Choose when recurring extras begin and when a lump sum is paid. Dates between scheduled payments are applied on the next due date; interest is still calculated in equal payment periods. The annual increase raises the regular scheduled amount after each full payment year. The baseline uses the same frequency and rate without extras, lump sums or growth. Prepayment limits and penalties are excluded.

Formula

Periodic rate i = (1 + r/c)^(c/f) - 1. Due = opening balance × (1 + i). Actual payment = min(due, regular payment × (1 + annual increase)^completed years + eligible extra + eligible lump sum). Interest saved = baseline interest - planned interest.

Worked example

For $1,200 at 0% over twelve monthly payments, regular P&I is $100. A $200 lump sum on the first due date reduces repayment to ten payments. Adding $50 each month instead reduces it to eight payments.

Frequently asked questions

When is a mid-month lump sum applied?

It is applied on the first scheduled due date on or after the entered date. A lender using daily accrual may credit an earlier date differently.

What if I put the lump sum after payoff?

It is not applied because there is no balance left to repay. The schedule shows every payment actually used.

Are prepayment penalties included?

No. Check the agreement's limits and use the mortgage penalty calculator when a proposed payment exceeds them.

Sources

Written byAmira MansourCalculator writer. Builds and tests Mathulate calculators against published sources.

Reviewed byDavid Tremblay, CFAMortgage analyst. Checks formulas and worked examples against lender schedules.

Last updated November 1, 2026.