$155,000 mortgage at 3%

30-year fixed at 3%. At this week's 7.03% average the payment would be $1,034.34 (−$380.86 a month at 3%).

Principal and interest

$653.49 a month

Total interest over 30 years
$80,255
Total loan payments
$235,255
Interest per dollar of loan payments
34¢

Source: Freddie Mac Primary Mortgage Market Survey, week of September 24, 2026. An average, not an offer.

Change the numbers

Payment on $155,000 at nearby rates

30-year fixed; difference compared with this week's average
RateMonthly paymentDifferenceTotal interest
3.00% this page $653.49−$380.86$80,255
3.25% $674.57−$359.77$87,845
3.50% $696.02−$338.32$95,567
3.75% $717.83−$316.51$103,419
4.00% $739.99−$294.35$111,398
7.03% this week's average $1,034.34$0.00$217,364

Other terms at 3%

TermRateMonthly paymentTotal interestTotal paid
15-year fixed 3.00%$1,070.40$37,672$192,672
20-year fixed 3.00%$859.63$51,310$206,310
30-year fixed 3.00%$653.49$80,255$235,255

With taxes

Assumes the $155,000 loan is 80% of a $193,750 purchase (20% down, so no PMI).
Principal and interest$653.49
Property tax 0.78% a year, estimate$125.94
Homeowners insurancenot included
Monthly subtotal before insurance/HOA$779.42

Estimate: the median of the 32 state rates we have sourced. Insurance is left out because we have no sourced average for this estimate yet; add your own quote.

Enter your insurance, property tax, HOA and PMI quotes · Estimate conventional PMI request and termination milestones

Income needed

To keep the $779.42 monthly housing cost at 28% of gross income, you'd need about $33,404 a year. Lenders also cap total debt payments near 36% of income, so car and student loan payments reduce what you can borrow.

Amortization schedule

Create a dated schedule with extra payments

Payment totals include regular principal, extra principal and interest. Annual lump sums are part of the Extra column. CSV separates monthly and annual extras. Calculations keep full precision; displayed rows and totals are rounded independently.

Principal repaid, including any extra principal payment, first exceeds interest at payment 84. The chart below compares totals for each loan year.

Principal and interest paid each year on a $155,000 mortgageEach column is one loan year, split into principal repaid and interest paid. Annual principal repaid, including extra payments, first exceeds annual interest in year 8.$0$2k$4k$6k$8kYear 1: principal $3,236, interest $4,606, balance after $151,764Year 1Year 2: principal $3,335, interest $4,507, balance after $148,429Year 3: principal $3,436, interest $4,406, balance after $144,993Year 4: principal $3,540, interest $4,301, balance after $141,453Year 5: principal $3,648, interest $4,194, balance after $137,8055Year 6: principal $3,759, interest $4,083, balance after $134,046Year 7: principal $3,873, interest $3,968, balance after $130,172Year 8: principal $3,991, interest $3,851, balance after $126,181Year 9: principal $4,113, interest $3,729, balance after $122,068Year 10: principal $4,238, interest $3,604, balance after $117,83110Year 11: principal $4,367, interest $3,475, balance after $113,464Year 12: principal $4,499, interest $3,342, balance after $108,965Year 13: principal $4,636, interest $3,206, balance after $104,328Year 14: principal $4,777, interest $3,065, balance after $99,551Year 15: principal $4,923, interest $2,919, balance after $94,62815Year 16: principal $5,072, interest $2,769, balance after $89,556Year 17: principal $5,227, interest $2,615, balance after $84,329Year 18: principal $5,386, interest $2,456, balance after $78,944Year 19: principal $5,549, interest $2,292, balance after $73,394Year 20: principal $5,718, interest $2,124, balance after $67,67620Year 21: principal $5,892, interest $1,950, balance after $61,784Year 22: principal $6,071, interest $1,770, balance after $55,713Year 23: principal $6,256, interest $1,586, balance after $49,457Year 24: principal $6,446, interest $1,396, balance after $43,010Year 25: principal $6,642, interest $1,199, balance after $36,36825Year 26: principal $6,844, interest $997, balance after $29,524Year 27: principal $7,053, interest $789, balance after $22,471Year 28: principal $7,267, interest $575, balance after $15,204Year 29: principal $7,488, interest $354, balance after $7,716Year 30: principal $7,716, interest $126, balance after $030

First 12 months

Amortization schedule for a $155,000 mortgage at 3.00% over 30 years, months 1–12; first payment $653.49. The final payment may be smaller.
PaymentTotal paymentRegular principalExtraInterestBalance
1$653.49$265.99$0.00$387.50$154,734.01
2$653.49$266.65$0.00$386.84$154,467.36
3$653.49$267.32$0.00$386.17$154,200.04
4$653.49$267.99$0.00$385.50$153,932.06
5$653.49$268.66$0.00$384.83$153,663.40
6$653.49$269.33$0.00$384.16$153,394.07
7$653.49$270.00$0.00$383.49$153,124.07
8$653.49$270.68$0.00$382.81$152,853.40
9$653.49$271.35$0.00$382.13$152,582.04
10$653.49$272.03$0.00$381.46$152,310.01
11$653.49$272.71$0.00$380.78$152,037.30
12$653.49$273.39$0.00$380.09$151,763.91

Year by year

Totals for each loan year
Loan yearTotal paidPrincipal incl. extrasInterestBalance at year end
1$7,842$3,236$4,606$151,764
2$7,842$3,335$4,507$148,429
3$7,842$3,436$4,406$144,993
4$7,842$3,540$4,301$141,453
5$7,842$3,648$4,194$137,805
6$7,842$3,759$4,083$134,046
7$7,842$3,873$3,968$130,172
8$7,842$3,991$3,851$126,181
9$7,842$4,113$3,729$122,068
10$7,842$4,238$3,604$117,831
11$7,842$4,367$3,475$113,464
12$7,842$4,499$3,342$108,965
13$7,842$4,636$3,206$104,328
14$7,842$4,777$3,065$99,551
15$7,842$4,923$2,919$94,628
16$7,842$5,072$2,769$89,556
17$7,842$5,227$2,615$84,329
18$7,842$5,386$2,456$78,944
19$7,842$5,549$2,292$73,394
20$7,842$5,718$2,124$67,676
21$7,842$5,892$1,950$61,784
22$7,842$6,071$1,770$55,713
23$7,842$6,256$1,586$49,457
24$7,842$6,446$1,396$43,010
25$7,842$6,642$1,199$36,368
26$7,842$6,844$997$29,524
27$7,842$7,053$789$22,471
28$7,842$7,267$575$15,204
29$7,842$7,488$354$7,716
30$7,842$7,716$126$0
Total$235,255$155,000$80,255$0
Balance remaining on a $155,000 mortgage over 30 yearsThe loan balance left at the end of each year, from $155,000 down to $0.$0$50k$100k$150k$200kStartYear 15Year 30Balance, Start: $155kBalance, Year 1: $151.8kBalance, Year 2: $148.4kBalance, Year 3: $145kBalance, Year 4: $141.5kBalance, Year 5: $137.8kBalance, Year 6: $134kBalance, Year 7: $130.2kBalance, Year 8: $126.2kBalance, Year 9: $122.1kBalance, Year 10: $117.8kBalance, Year 11: $113.5kBalance, Year 12: $109kBalance, Year 13: $104.3kBalance, Year 14: $99.6kBalance, Year 15: $94.6kBalance, Year 16: $89.6kBalance, Year 17: $84.3kBalance, Year 18: $78.9kBalance, Year 19: $73.4kBalance, Year 20: $67.7kBalance, Year 21: $61.8kBalance, Year 22: $55.7kBalance, Year 23: $49.5kBalance, Year 24: $43kBalance, Year 25: $36.4kBalance, Year 26: $29.5kBalance, Year 27: $22.5kBalance, Year 28: $15.2kBalance, Year 29: $7.7kBalance, Year 30: $0
Full schedule, all 360 payments
Amortization schedule for a $155,000 mortgage at 3.00% over 30 years, every payment
PaymentTotal paymentRegular principalExtraInterestBalance
1653.49265.990.00387.50154,734.01
2653.49266.650.00386.84154,467.36
3653.49267.320.00386.17154,200.04
4653.49267.990.00385.50153,932.06
5653.49268.660.00384.83153,663.40
6653.49269.330.00384.16153,394.07
7653.49270.000.00383.49153,124.07
8653.49270.680.00382.81152,853.40
9653.49271.350.00382.13152,582.04
10653.49272.030.00381.46152,310.01
11653.49272.710.00380.78152,037.30
12653.49273.390.00380.09151,763.91
13653.49274.080.00379.41151,489.83
14653.49274.760.00378.72151,215.07
15653.49275.450.00378.04150,939.62
16653.49276.140.00377.35150,663.49
17653.49276.830.00376.66150,386.66
18653.49277.520.00375.97150,109.14
19653.49278.210.00375.27149,830.92
20653.49278.910.00374.58149,552.02
21653.49279.610.00373.88149,272.41
22653.49280.310.00373.18148,992.10
23653.49281.010.00372.48148,711.10
24653.49281.710.00371.78148,429.39
25653.49282.410.00371.07148,146.98
26653.49283.120.00370.37147,863.86
27653.49283.830.00369.66147,580.03
28653.49284.540.00368.95147,295.50
29653.49285.250.00368.24147,010.25
30653.49285.960.00367.53146,724.29
31653.49286.680.00366.81146,437.61
32653.49287.390.00366.09146,150.22
33653.49288.110.00365.38145,862.11
34653.49288.830.00364.66145,573.28
35653.49289.550.00363.93145,283.73
36653.49290.280.00363.21144,993.45
37653.49291.000.00362.48144,702.45
38653.49291.730.00361.76144,410.72
39653.49292.460.00361.03144,118.26
40653.49293.190.00360.30143,825.07
41653.49293.920.00359.56143,531.14
42653.49294.660.00358.83143,236.48
43653.49295.400.00358.09142,941.09
44653.49296.130.00357.35142,644.95
45653.49296.870.00356.61142,348.08
46653.49297.620.00355.87142,050.46
47653.49298.360.00355.13141,752.10
48653.49299.110.00354.38141,453.00
49653.49299.850.00353.63141,153.14
50653.49300.600.00352.88140,852.54
51653.49301.350.00352.13140,551.19
52653.49302.110.00351.38140,249.08
53653.49302.860.00350.62139,946.21
54653.49303.620.00349.87139,642.59
55653.49304.380.00349.11139,338.21
56653.49305.140.00348.35139,033.07
57653.49305.900.00347.58138,727.17
58653.49306.670.00346.82138,420.50
59653.49307.430.00346.05138,113.07
60653.49308.200.00345.28137,804.86
61653.49308.970.00344.51137,495.89
62653.49309.750.00343.74137,186.14
63653.49310.520.00342.97136,875.62
64653.49311.300.00342.19136,564.32
65653.49312.080.00341.41136,252.25
66653.49312.860.00340.63135,939.39
67653.49313.640.00339.85135,625.76
68653.49314.420.00339.06135,311.33
69653.49315.210.00338.28134,996.13
70653.49316.000.00337.49134,680.13
71653.49316.790.00336.70134,363.34
72653.49317.580.00335.91134,045.77
73653.49318.370.00335.11133,727.39
74653.49319.170.00334.32133,408.23
75653.49319.970.00333.52133,088.26
76653.49320.770.00332.72132,767.50
77653.49321.570.00331.92132,445.93
78653.49322.370.00331.11132,123.56
79653.49323.180.00330.31131,800.38
80653.49323.990.00329.50131,476.39
81653.49324.800.00328.69131,151.60
82653.49325.610.00327.88130,825.99
83653.49326.420.00327.06130,499.57
84653.49327.240.00326.25130,172.33
85653.49328.060.00325.43129,844.28
86653.49328.880.00324.61129,515.40
87653.49329.700.00323.79129,185.70
88653.49330.520.00322.96128,855.18
89653.49331.350.00322.14128,523.83
90653.49332.180.00321.31128,191.66
91653.49333.010.00320.48127,858.65
92653.49333.840.00319.65127,524.81
93653.49334.670.00318.81127,190.14
94653.49335.510.00317.98126,854.62
95653.49336.350.00317.14126,518.28
96653.49337.190.00316.30126,181.08
97653.49338.030.00315.45125,843.05
98653.49338.880.00314.61125,504.17
99653.49339.730.00313.76125,164.45
100653.49340.580.00312.91124,823.87
101653.49341.430.00312.06124,482.44
102653.49342.280.00311.21124,140.16
103653.49343.140.00310.35123,797.03
104653.49343.990.00309.49123,453.04
105653.49344.850.00308.63123,108.18
106653.49345.720.00307.77122,762.47
107653.49346.580.00306.91122,415.89
108653.49347.450.00306.04122,068.44
109653.49348.320.00305.17121,720.12
110653.49349.190.00304.30121,370.94
111653.49350.060.00303.43121,020.88
112653.49350.930.00302.55120,669.95
113653.49351.810.00301.67120,318.13
114653.49352.690.00300.80119,965.44
115653.49353.570.00299.91119,611.87
116653.49354.460.00299.03119,257.41
117653.49355.340.00298.14118,902.07
118653.49356.230.00297.26118,545.84
119653.49357.120.00296.36118,188.72
120653.49358.010.00295.47117,830.70
121653.49358.910.00294.58117,471.79
122653.49359.810.00293.68117,111.99
123653.49360.710.00292.78116,751.28
124653.49361.610.00291.88116,389.67
125653.49362.510.00290.97116,027.16
126653.49363.420.00290.07115,663.74
127653.49364.330.00289.16115,299.42
128653.49365.240.00288.25114,934.18
129653.49366.150.00287.34114,568.03
130653.49367.070.00286.42114,200.96
131653.49367.980.00285.50113,832.98
132653.49368.900.00284.58113,464.07
133653.49369.830.00283.66113,094.25
134653.49370.750.00282.74112,723.50
135653.49371.680.00281.81112,351.82
136653.49372.610.00280.88111,979.21
137653.49373.540.00279.95111,605.67
138653.49374.470.00279.01111,231.20
139653.49375.410.00278.08110,855.79
140653.49376.350.00277.14110,479.45
141653.49377.290.00276.20110,102.16
142653.49378.230.00275.26109,723.93
143653.49379.180.00274.31109,344.75
144653.49380.120.00273.36108,964.63
145653.49381.070.00272.41108,583.55
146653.49382.030.00271.46108,201.53
147653.49382.980.00270.50107,818.54
148653.49383.940.00269.55107,434.60
149653.49384.900.00268.59107,049.70
150653.49385.860.00267.62106,663.84
151653.49386.830.00266.66106,277.02
152653.49387.790.00265.69105,889.22
153653.49388.760.00264.72105,500.46
154653.49389.740.00263.75105,110.72
155653.49390.710.00262.78104,720.01
156653.49391.690.00261.80104,328.33
157653.49392.670.00260.82103,935.66
158653.49393.650.00259.84103,542.01
159653.49394.630.00258.86103,147.38
160653.49395.620.00257.87102,751.77
161653.49396.610.00256.88102,355.16
162653.49397.600.00255.89101,957.56
163653.49398.590.00254.89101,558.97
164653.49399.590.00253.90101,159.38
165653.49400.590.00252.90100,758.79
166653.49401.590.00251.90100,357.20
167653.49402.590.00250.8999,954.61
168653.49403.600.00249.8999,551.01
169653.49404.610.00248.8899,146.40
170653.49405.620.00247.8798,740.78
171653.49406.630.00246.8598,334.15
172653.49407.650.00245.8497,926.50
173653.49408.670.00244.8297,517.83
174653.49409.690.00243.7997,108.13
175653.49410.720.00242.7796,697.42
176653.49411.740.00241.7496,285.68
177653.49412.770.00240.7195,872.90
178653.49413.800.00239.6895,459.10
179653.49414.840.00238.6595,044.26
180653.49415.880.00237.6194,628.38
181653.49416.920.00236.5794,211.47
182653.49417.960.00235.5393,793.51
183653.49419.000.00234.4893,374.51
184653.49420.050.00233.4492,954.46
185653.49421.100.00232.3992,533.36
186653.49422.150.00231.3392,111.21
187653.49423.210.00230.2891,688.00
188653.49424.270.00229.2291,263.73
189653.49425.330.00228.1690,838.41
190653.49426.390.00227.1090,412.01
191653.49427.460.00226.0389,984.56
192653.49428.520.00224.9689,556.03
193653.49429.600.00223.8989,126.44
194653.49430.670.00222.8288,695.77
195653.49431.750.00221.7488,264.02
196653.49432.830.00220.6687,831.19
197653.49433.910.00219.5887,397.29
198653.49434.990.00218.4986,962.29
199653.49436.080.00217.4186,526.21
200653.49437.170.00216.3286,089.04
201653.49438.260.00215.2285,650.78
202653.49439.360.00214.1385,211.42
203653.49440.460.00213.0384,770.96
204653.49441.560.00211.9384,329.40
205653.49442.660.00210.8283,886.74
206653.49443.770.00209.7283,442.97
207653.49444.880.00208.6182,998.09
208653.49445.990.00207.5082,552.10
209653.49447.110.00206.3882,104.99
210653.49448.220.00205.2681,656.77
211653.49449.340.00204.1481,207.43
212653.49450.470.00203.0280,756.96
213653.49451.590.00201.8980,305.36
214653.49452.720.00200.7679,852.64
215653.49453.850.00199.6379,398.79
216653.49454.990.00198.5078,943.80
217653.49456.130.00197.3678,487.67
218653.49457.270.00196.2278,030.40
219653.49458.410.00195.0877,571.99
220653.49459.560.00193.9377,112.44
221653.49460.710.00192.7876,651.73
222653.49461.860.00191.6376,189.88
223653.49463.010.00190.4775,726.86
224653.49464.170.00189.3275,262.69
225653.49465.330.00188.1674,797.37
226653.49466.490.00186.9974,330.87
227653.49467.660.00185.8373,863.21
228653.49468.830.00184.6673,394.39
229653.49470.000.00183.4972,924.39
230653.49471.180.00182.3172,453.21
231653.49472.350.00181.1371,980.86
232653.49473.530.00179.9571,507.32
233653.49474.720.00178.7771,032.60
234653.49475.900.00177.5870,556.70
235653.49477.090.00176.3970,079.61
236653.49478.290.00175.2069,601.32
237653.49479.480.00174.0069,121.84
238653.49480.680.00172.8068,641.15
239653.49481.880.00171.6068,159.27
240653.49483.090.00170.4067,676.18
241653.49484.300.00169.1967,191.89
242653.49485.510.00167.9866,706.38
243653.49486.720.00166.7766,219.66
244653.49487.940.00165.5565,731.72
245653.49489.160.00164.3365,242.57
246653.49490.380.00163.1164,752.19
247653.49491.610.00161.8864,260.58
248653.49492.830.00160.6563,767.74
249653.49494.070.00159.4263,273.68
250653.49495.300.00158.1862,778.38
251653.49496.540.00156.9562,281.84
252653.49497.780.00155.7061,784.05
253653.49499.030.00154.4661,285.03
254653.49500.270.00153.2160,784.75
255653.49501.520.00151.9660,283.23
256653.49502.780.00150.7159,780.45
257653.49504.040.00149.4559,276.42
258653.49505.300.00148.1958,771.12
259653.49506.560.00146.9358,264.56
260653.49507.820.00145.6657,756.74
261653.49509.090.00144.3957,247.64
262653.49510.370.00143.1256,737.28
263653.49511.640.00141.8456,225.63
264653.49512.920.00140.5655,712.71
265653.49514.200.00139.2855,198.51
266653.49515.490.00138.0054,683.02
267653.49516.780.00136.7154,166.24
268653.49518.070.00135.4253,648.17
269653.49519.370.00134.1253,128.80
270653.49520.660.00132.8252,608.14
271653.49521.970.00131.5252,086.17
272653.49523.270.00130.2251,562.90
273653.49524.580.00128.9151,038.32
274653.49525.890.00127.6050,512.43
275653.49527.210.00126.2849,985.23
276653.49528.520.00124.9649,456.70
277653.49529.840.00123.6448,926.86
278653.49531.170.00122.3248,395.69
279653.49532.500.00120.9947,863.19
280653.49533.830.00119.6647,329.36
281653.49535.160.00118.3246,794.20
282653.49536.500.00116.9946,257.70
283653.49537.840.00115.6445,719.86
284653.49539.190.00114.3045,180.67
285653.49540.530.00112.9544,640.14
286653.49541.890.00111.6044,098.25
287653.49543.240.00110.2543,555.01
288653.49544.600.00108.8943,010.41
289653.49545.960.00107.5342,464.45
290653.49547.330.00106.1641,917.13
291653.49548.690.00104.7941,368.43
292653.49550.070.00103.4240,818.37
293653.49551.440.00102.0540,266.93
294653.49552.820.00100.6739,714.11
295653.49554.200.0099.2939,159.91
296653.49555.590.0097.9038,604.32
297653.49556.980.0096.5138,047.35
298653.49558.370.0095.1237,488.98
299653.49559.760.0093.7236,929.21
300653.49561.160.0092.3236,368.05
301653.49562.570.0090.9235,805.48
302653.49563.970.0089.5135,241.51
303653.49565.380.0088.1034,676.13
304653.49566.800.0086.6934,109.33
305653.49568.210.0085.2733,541.12
306653.49569.630.0083.8532,971.49
307653.49571.060.0082.4332,400.43
308653.49572.490.0081.0031,827.94
309653.49573.920.0079.5731,254.03
310653.49575.350.0078.1430,678.68
311653.49576.790.0076.7030,101.89
312653.49578.230.0075.2529,523.66
313653.49579.680.0073.8128,943.98
314653.49581.130.0072.3628,362.85
315653.49582.580.0070.9127,780.27
316653.49584.040.0069.4527,196.24
317653.49585.500.0067.9926,610.74
318653.49586.960.0066.5326,023.78
319653.49588.430.0065.0625,435.36
320653.49589.900.0063.5924,845.46
321653.49591.370.0062.1124,254.09
322653.49592.850.0060.6423,661.23
323653.49594.330.0059.1523,066.90
324653.49595.820.0057.6722,471.08
325653.49597.310.0056.1821,873.77
326653.49598.800.0054.6821,274.97
327653.49600.300.0053.1920,674.67
328653.49601.800.0051.6920,072.87
329653.49603.300.0050.1819,469.57
330653.49604.810.0048.6718,864.76
331653.49606.320.0047.1618,258.43
332653.49607.840.0045.6517,650.59
333653.49609.360.0044.1317,041.23
334653.49610.880.0042.6016,430.35
335653.49612.410.0041.0815,817.94
336653.49613.940.0039.5415,204.00
337653.49615.480.0038.0114,588.52
338653.49617.010.0036.4713,971.51
339653.49618.560.0034.9313,352.95
340653.49620.100.0033.3812,732.85
341653.49621.650.0031.8312,111.19
342653.49623.210.0030.2811,487.98
343653.49624.770.0028.7210,863.22
344653.49626.330.0027.1610,236.89
345653.49627.890.0025.599,608.99
346653.49629.460.0024.028,979.53
347653.49631.040.0022.458,348.49
348653.49632.620.0020.877,715.88
349653.49634.200.0019.297,081.68
350653.49635.780.0017.706,445.90
351653.49637.370.0016.115,808.53
352653.49638.960.0014.525,169.56
353653.49640.560.0012.924,529.00
354653.49642.160.0011.323,886.84
355653.49643.770.009.723,243.07
356653.49645.380.008.112,597.69
357653.49646.990.006.491,950.70
358653.49648.610.004.881,302.09
359653.49650.230.003.26651.86
360653.49651.860.001.630.00

Compare a refinance with your remaining loan · Compare two rate-and-points quotes

Questions

How much is a $155,000 mortgage per month?

At 3.00%, a 30-year $155,000 mortgage costs $653.49 a month in principal and interest. Property tax and insurance add about $125.94 a month on a $193,750 home, for about $779.42 in total.

How much income do I need for a $155,000 mortgage?

About $33,404 a year, if housing costs ($779.42 a month including estimated tax) stay at 28% of gross income. Other debts lower what lenders will approve under the 36% total-debt guideline.

How much interest will I pay on a $155,000 mortgage?

$80,255 over 30 years at 3.00%. A 15-year loan at 3.00% cuts that to $37,672, but the payment rises to $1,070.40.

What is the payment on a $155,000 mortgage at 2%?

$572.91 a month over 30 years, −$80.58 compared with 3.00%. Total interest would be $51,248.

How much faster is a $155,000 mortgage paid off with $100 extra a month?

Adding $100 to every payment pays the loan off in 24 years 2 months instead of 30 years and saves about $17,341 in interest at 3.00%.

Is this rate an offer?

No. 7.03% is the Freddie Mac weekly average for 30-year fixed loans with about 20% down and strong credit. Lenders price each borrower individually; your quote can be higher or lower.

Sources

Page calculations or content last changed September 27, 2026. Observation and retrieval dates are listed per source above. How we calculate.