$175,000 mortgage at 3%

30-year fixed at 3%. At this week's 7.03% average the payment would be $1,167.81 (−$430.00 a month at 3%).

Principal and interest

$737.81 a month

Total interest over 30 years
$90,611
Total loan payments
$265,611
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 $175,000 at nearby rates

30-year fixed; difference compared with this week's average
RateMonthly paymentDifferenceTotal interest
3.00% this page $737.81−$430.00$90,611
3.25% $761.61−$406.20$99,180
3.50% $785.83−$381.98$107,898
3.75% $810.45−$357.36$116,763
4.00% $835.48−$332.33$125,772
7.03% this week's average $1,167.81$0.00$245,411

Other terms at 3%

TermRateMonthly paymentTotal interestTotal paid
15-year fixed 3.00%$1,208.52$42,533$217,533
20-year fixed 3.00%$970.55$57,931$232,931
30-year fixed 3.00%$737.81$90,611$265,611

With taxes

Assumes the $175,000 loan is 80% of a $218,750 purchase (20% down, so no PMI).
Principal and interest$737.81
Property tax 0.78% a year, estimate$142.19
Homeowners insurancenot included
Monthly subtotal before insurance/HOA$879.99

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 $879.99 monthly housing cost at 28% of gross income, you'd need about $37,714 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 $175,000 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$8k$10kYear 1: principal $3,654, interest $5,200, balance after $171,346Year 1Year 2: principal $3,765, interest $5,089, balance after $167,582Year 3: principal $3,879, interest $4,974, balance after $163,702Year 4: principal $3,997, interest $4,856, balance after $159,705Year 5: principal $4,119, interest $4,735, balance after $155,5865Year 6: principal $4,244, interest $4,610, balance after $151,342Year 7: principal $4,373, interest $4,480, balance after $146,969Year 8: principal $4,506, interest $4,347, balance after $142,463Year 9: principal $4,643, interest $4,210, balance after $137,819Year 10: principal $4,785, interest $4,069, balance after $133,03510Year 11: principal $4,930, interest $3,924, balance after $128,105Year 12: principal $5,080, interest $3,774, balance after $123,025Year 13: principal $5,235, interest $3,619, balance after $117,790Year 14: principal $5,394, interest $3,460, balance after $112,396Year 15: principal $5,558, interest $3,296, balance after $106,83815Year 16: principal $5,727, interest $3,127, balance after $101,112Year 17: principal $5,901, interest $2,953, balance after $95,211Year 18: principal $6,081, interest $2,773, balance after $89,130Year 19: principal $6,265, interest $2,588, balance after $82,865Year 20: principal $6,456, interest $2,398, balance after $76,40920Year 21: principal $6,652, interest $2,201, balance after $69,756Year 22: principal $6,855, interest $1,999, balance after $62,901Year 23: principal $7,063, interest $1,790, balance after $55,838Year 24: principal $7,278, interest $1,576, balance after $48,560Year 25: principal $7,499, interest $1,354, balance after $41,06125Year 26: principal $7,728, interest $1,126, balance after $33,333Year 27: principal $7,963, interest $891, balance after $25,371Year 28: principal $8,205, interest $649, balance after $17,166Year 29: principal $8,454, interest $399, balance after $8,711Year 30: principal $8,711, interest $142, balance after $030

First 12 months

Amortization schedule for a $175,000 mortgage at 3.00% over 30 years, months 1–12; first payment $737.81. The final payment may be smaller.
PaymentTotal paymentRegular principalExtraInterestBalance
1$737.81$300.31$0.00$437.50$174,699.69
2$737.81$301.06$0.00$436.75$174,398.64
3$737.81$301.81$0.00$436.00$174,096.82
4$737.81$302.56$0.00$435.24$173,794.26
5$737.81$303.32$0.00$434.49$173,490.94
6$737.81$304.08$0.00$433.73$173,186.86
7$737.81$304.84$0.00$432.97$172,882.02
8$737.81$305.60$0.00$432.21$172,576.42
9$737.81$306.37$0.00$431.44$172,270.05
10$737.81$307.13$0.00$430.68$171,962.92
11$737.81$307.90$0.00$429.91$171,655.02
12$737.81$308.67$0.00$429.14$171,346.35

Year by year

Totals for each loan year
Loan yearTotal paidPrincipal incl. extrasInterestBalance at year end
1$8,854$3,654$5,200$171,346
2$8,854$3,765$5,089$167,582
3$8,854$3,879$4,974$163,702
4$8,854$3,997$4,856$159,705
5$8,854$4,119$4,735$155,586
6$8,854$4,244$4,610$151,342
7$8,854$4,373$4,480$146,969
8$8,854$4,506$4,347$142,463
9$8,854$4,643$4,210$137,819
10$8,854$4,785$4,069$133,035
11$8,854$4,930$3,924$128,105
12$8,854$5,080$3,774$123,025
13$8,854$5,235$3,619$117,790
14$8,854$5,394$3,460$112,396
15$8,854$5,558$3,296$106,838
16$8,854$5,727$3,127$101,112
17$8,854$5,901$2,953$95,211
18$8,854$6,081$2,773$89,130
19$8,854$6,265$2,588$82,865
20$8,854$6,456$2,398$76,409
21$8,854$6,652$2,201$69,756
22$8,854$6,855$1,999$62,901
23$8,854$7,063$1,790$55,838
24$8,854$7,278$1,576$48,560
25$8,854$7,499$1,354$41,061
26$8,854$7,728$1,126$33,333
27$8,854$7,963$891$25,371
28$8,854$8,205$649$17,166
29$8,854$8,454$399$8,711
30$8,854$8,711$142$0
Total$265,611$175,000$90,611$0
Balance remaining on a $175,000 mortgage over 30 yearsThe loan balance left at the end of each year, from $175,000 down to $0.$0$50k$100k$150k$200kStartYear 15Year 30Balance, Start: $175kBalance, Year 1: $171.3kBalance, Year 2: $167.6kBalance, Year 3: $163.7kBalance, Year 4: $159.7kBalance, Year 5: $155.6kBalance, Year 6: $151.3kBalance, Year 7: $147kBalance, Year 8: $142.5kBalance, Year 9: $137.8kBalance, Year 10: $133kBalance, Year 11: $128.1kBalance, Year 12: $123kBalance, Year 13: $117.8kBalance, Year 14: $112.4kBalance, Year 15: $106.8kBalance, Year 16: $101.1kBalance, Year 17: $95.2kBalance, Year 18: $89.1kBalance, Year 19: $82.9kBalance, Year 20: $76.4kBalance, Year 21: $69.8kBalance, Year 22: $62.9kBalance, Year 23: $55.8kBalance, Year 24: $48.6kBalance, Year 25: $41.1kBalance, Year 26: $33.3kBalance, Year 27: $25.4kBalance, Year 28: $17.2kBalance, Year 29: $8.7kBalance, Year 30: $0
Full schedule, all 360 payments
Amortization schedule for a $175,000 mortgage at 3.00% over 30 years, every payment
PaymentTotal paymentRegular principalExtraInterestBalance
1737.81300.310.00437.50174,699.69
2737.81301.060.00436.75174,398.64
3737.81301.810.00436.00174,096.82
4737.81302.560.00435.24173,794.26
5737.81303.320.00434.49173,490.94
6737.81304.080.00433.73173,186.86
7737.81304.840.00432.97172,882.02
8737.81305.600.00432.21172,576.42
9737.81306.370.00431.44172,270.05
10737.81307.130.00430.68171,962.92
11737.81307.900.00429.91171,655.02
12737.81308.670.00429.14171,346.35
13737.81309.440.00428.37171,036.91
14737.81310.210.00427.59170,726.69
15737.81310.990.00426.82170,415.70
16737.81311.770.00426.04170,103.94
17737.81312.550.00425.26169,791.39
18737.81313.330.00424.48169,478.06
19737.81314.110.00423.70169,163.95
20737.81314.900.00422.91168,849.05
21737.81315.680.00422.12168,533.37
22737.81316.470.00421.33168,216.89
23737.81317.260.00420.54167,899.63
24737.81318.060.00419.75167,581.57
25737.81318.850.00418.95167,262.72
26737.81319.650.00418.16166,943.07
27737.81320.450.00417.36166,622.62
28737.81321.250.00416.56166,301.37
29737.81322.050.00415.75165,979.31
30737.81322.860.00414.95165,656.45
31737.81323.670.00414.14165,332.79
32737.81324.480.00413.33165,008.31
33737.81325.290.00412.52164,683.03
34737.81326.100.00411.71164,356.93
35737.81326.910.00410.89164,030.01
36737.81327.730.00410.08163,702.28
37737.81328.550.00409.26163,373.73
38737.81329.370.00408.43163,044.36
39737.81330.200.00407.61162,714.16
40737.81331.020.00406.79162,383.14
41737.81331.850.00405.96162,051.29
42737.81332.680.00405.13161,718.61
43737.81333.510.00404.30161,385.10
44737.81334.340.00403.46161,050.76
45737.81335.180.00402.63160,715.58
46737.81336.020.00401.79160,379.56
47737.81336.860.00400.95160,042.70
48737.81337.700.00400.11159,705.00
49737.81338.540.00399.26159,366.45
50737.81339.390.00398.42159,027.06
51737.81340.240.00397.57158,686.82
52737.81341.090.00396.72158,345.73
53737.81341.940.00395.86158,003.79
54737.81342.800.00395.01157,660.99
55737.81343.650.00394.15157,317.34
56737.81344.510.00393.29156,972.83
57737.81345.370.00392.43156,627.45
58737.81346.240.00391.57156,281.21
59737.81347.100.00390.70155,934.11
60737.81347.970.00389.84155,586.14
61737.81348.840.00388.97155,237.29
62737.81349.710.00388.09154,887.58
63737.81350.590.00387.22154,536.99
64737.81351.460.00386.34154,185.53
65737.81352.340.00385.46153,833.18
66737.81353.220.00384.58153,479.96
67737.81354.110.00383.70153,125.85
68737.81354.990.00382.81152,770.86
69737.81355.880.00381.93152,414.98
70737.81356.770.00381.04152,058.21
71737.81357.660.00380.15151,700.55
72737.81358.560.00379.25151,341.99
73737.81359.450.00378.35150,982.54
74737.81360.350.00377.46150,622.19
75737.81361.250.00376.56150,260.94
76737.81362.150.00375.65149,898.78
77737.81363.060.00374.75149,535.72
78737.81363.970.00373.84149,171.76
79737.81364.880.00372.93148,806.88
80737.81365.790.00372.02148,441.09
81737.81366.700.00371.10148,074.39
82737.81367.620.00370.19147,706.76
83737.81368.540.00369.27147,338.22
84737.81369.460.00368.35146,968.76
85737.81370.390.00367.42146,598.38
86737.81371.310.00366.50146,227.07
87737.81372.240.00365.57145,854.83
88737.81373.170.00364.64145,481.66
89737.81374.100.00363.70145,107.55
90737.81375.040.00362.77144,732.52
91737.81375.980.00361.83144,356.54
92737.81376.920.00360.89143,979.62
93737.81377.860.00359.95143,601.77
94737.81378.800.00359.00143,222.96
95737.81379.750.00358.06142,843.21
96737.81380.700.00357.11142,462.51
97737.81381.650.00356.16142,080.86
98737.81382.600.00355.20141,698.26
99737.81383.560.00354.25141,314.70
100737.81384.520.00353.29140,930.18
101737.81385.480.00352.33140,544.70
102737.81386.450.00351.36140,158.25
103737.81387.410.00350.40139,770.84
104737.81388.380.00349.43139,382.46
105737.81389.350.00348.46138,993.11
106737.81390.320.00347.48138,602.78
107737.81391.300.00346.51138,211.48
108737.81392.280.00345.53137,819.21
109737.81393.260.00344.55137,425.95
110737.81394.240.00343.56137,031.70
111737.81395.230.00342.58136,636.48
112737.81396.220.00341.59136,240.26
113737.81397.210.00340.60135,843.05
114737.81398.200.00339.61135,444.85
115737.81399.190.00338.61135,045.66
116737.81400.190.00337.61134,645.47
117737.81401.190.00336.61134,244.27
118737.81402.200.00335.61133,842.08
119737.81403.200.00334.61133,438.88
120737.81404.210.00333.60133,034.67
121737.81405.220.00332.59132,629.45
122737.81406.230.00331.57132,223.21
123737.81407.250.00330.56131,815.96
124737.81408.270.00329.54131,407.70
125737.81409.290.00328.52130,998.41
126737.81410.310.00327.50130,588.10
127737.81411.340.00326.47130,176.76
128737.81412.370.00325.44129,764.39
129737.81413.400.00324.41129,351.00
130737.81414.430.00323.38128,936.57
131737.81415.470.00322.34128,521.10
132737.81416.500.00321.30128,104.60
133737.81417.550.00320.26127,687.05
134737.81418.590.00319.22127,268.46
135737.81419.640.00318.17126,848.83
136737.81420.680.00317.12126,428.14
137737.81421.740.00316.07126,006.41
138737.81422.790.00315.02125,583.62
139737.81423.850.00313.96125,159.77
140737.81424.910.00312.90124,734.86
141737.81425.970.00311.84124,308.89
142737.81427.030.00310.77123,881.86
143737.81428.100.00309.70123,453.75
144737.81429.170.00308.63123,024.58
145737.81430.250.00307.56122,594.33
146737.81431.320.00306.49122,163.01
147737.81432.400.00305.41121,730.61
148737.81433.480.00304.33121,297.13
149737.81434.560.00303.24120,862.57
150737.81435.650.00302.16120,426.92
151737.81436.740.00301.07119,990.18
152737.81437.830.00299.98119,552.35
153737.81438.930.00298.88119,113.42
154737.81440.020.00297.78118,673.40
155737.81441.120.00296.68118,232.27
156737.81442.230.00295.58117,790.05
157737.81443.330.00294.48117,346.72
158737.81444.440.00293.37116,902.27
159737.81445.550.00292.26116,456.72
160737.81446.670.00291.14116,010.06
161737.81447.780.00290.03115,562.28
162737.81448.900.00288.91115,113.38
163737.81450.020.00287.78114,663.35
164737.81451.150.00286.66114,212.20
165737.81452.280.00285.53113,759.93
166737.81453.410.00284.40113,306.52
167737.81454.540.00283.27112,851.98
168737.81455.680.00282.13112,396.30
169737.81456.820.00280.99111,939.48
170737.81457.960.00279.85111,481.53
171737.81459.100.00278.70111,022.42
172737.81460.250.00277.56110,562.17
173737.81461.400.00276.41110,100.77
174737.81462.560.00275.25109,638.22
175737.81463.710.00274.10109,174.50
176737.81464.870.00272.94108,709.63
177737.81466.030.00271.77108,243.60
178737.81467.200.00270.61107,776.40
179737.81468.370.00269.44107,308.04
180737.81469.540.00268.27106,838.50
181737.81470.710.00267.10106,367.79
182737.81471.890.00265.92105,895.90
183737.81473.070.00264.74105,422.83
184737.81474.250.00263.56104,948.58
185737.81475.440.00262.37104,473.15
186737.81476.620.00261.18103,996.52
187737.81477.820.00259.99103,518.71
188737.81479.010.00258.80103,039.70
189737.81480.210.00257.60102,559.49
190737.81481.410.00256.40102,078.08
191737.81482.610.00255.20101,595.47
192737.81483.820.00253.99101,111.65
193737.81485.030.00252.78100,626.62
194737.81486.240.00251.57100,140.38
195737.81487.460.00250.3599,652.93
196737.81488.670.00249.1399,164.25
197737.81489.900.00247.9198,674.36
198737.81491.120.00246.6998,183.23
199737.81492.350.00245.4697,690.89
200737.81493.580.00244.2397,197.31
201737.81494.810.00242.9996,702.49
202737.81496.050.00241.7696,206.44
203737.81497.290.00240.5295,709.15
204737.81498.530.00239.2795,210.62
205737.81499.780.00238.0394,710.84
206737.81501.030.00236.7894,209.81
207737.81502.280.00235.5293,707.52
208737.81503.540.00234.2793,203.98
209737.81504.800.00233.0192,699.19
210737.81506.060.00231.7592,193.13
211737.81507.320.00230.4891,685.80
212737.81508.590.00229.2191,177.21
213737.81509.860.00227.9490,667.35
214737.81511.140.00226.6790,156.21
215737.81512.420.00225.3989,643.79
216737.81513.700.00224.1189,130.09
217737.81514.980.00222.8388,615.11
218737.81516.270.00221.5488,098.84
219737.81517.560.00220.2587,581.28
220737.81518.850.00218.9587,062.43
221737.81520.150.00217.6686,542.28
222737.81521.450.00216.3686,020.83
223737.81522.750.00215.0585,498.07
224737.81524.060.00213.7584,974.01
225737.81525.370.00212.4484,448.64
226737.81526.690.00211.1283,921.95
227737.81528.000.00209.8083,393.95
228737.81529.320.00208.4882,864.63
229737.81530.650.00207.1682,333.98
230737.81531.970.00205.8381,802.01
231737.81533.300.00204.5181,268.71
232737.81534.640.00203.1780,734.07
233737.81535.970.00201.8480,198.10
234737.81537.310.00200.5079,660.79
235737.81538.660.00199.1579,122.13
236737.81540.000.00197.8178,582.13
237737.81541.350.00196.4678,040.78
238737.81542.710.00195.1077,498.08
239737.81544.060.00193.7576,954.01
240737.81545.420.00192.3976,408.59
241737.81546.790.00191.0275,861.81
242737.81548.150.00189.6575,313.65
243737.81549.520.00188.2874,764.13
244737.81550.900.00186.9174,213.23
245737.81552.270.00185.5373,660.96
246737.81553.650.00184.1573,107.31
247737.81555.040.00182.7772,552.27
248737.81556.430.00181.3871,995.84
249737.81557.820.00179.9971,438.02
250737.81559.210.00178.6070,878.81
251737.81560.610.00177.2070,318.20
252737.81562.010.00175.8069,756.19
253737.81563.420.00174.3969,192.77
254737.81564.830.00172.9868,627.95
255737.81566.240.00171.5768,061.71
256737.81567.650.00170.1567,494.06
257737.81569.070.00168.7466,924.99
258737.81570.490.00167.3166,354.49
259737.81571.920.00165.8965,782.57
260737.81573.350.00164.4665,209.22
261737.81574.780.00163.0264,634.44
262737.81576.220.00161.5964,058.22
263737.81577.660.00160.1563,480.55
264737.81579.110.00158.7062,901.45
265737.81580.550.00157.2562,320.89
266737.81582.000.00155.8061,738.89
267737.81583.460.00154.3561,155.43
268737.81584.920.00152.8960,570.51
269737.81586.380.00151.4359,984.13
270737.81587.850.00149.9659,396.28
271737.81589.320.00148.4958,806.97
272737.81590.790.00147.0258,216.18
273737.81592.270.00145.5457,623.91
274737.81593.750.00144.0657,030.16
275737.81595.230.00142.5856,434.93
276737.81596.720.00141.0955,838.21
277737.81598.210.00139.6055,240.00
278737.81599.710.00138.1054,640.29
279737.81601.210.00136.6054,039.09
280737.81602.710.00135.1053,436.38
281737.81604.220.00133.5952,832.16
282737.81605.730.00132.0852,226.44
283737.81607.240.00130.5751,619.19
284737.81608.760.00129.0551,010.44
285737.81610.280.00127.5350,400.15
286737.81611.810.00126.0049,788.35
287737.81613.340.00124.4749,175.01
288737.81614.870.00122.9448,560.14
289737.81616.410.00121.4047,943.74
290737.81617.950.00119.8647,325.79
291737.81619.490.00118.3146,706.30
292737.81621.040.00116.7746,085.25
293737.81622.590.00115.2145,462.66
294737.81624.150.00113.6644,838.51
295737.81625.710.00112.1044,212.80
296737.81627.280.00110.5343,585.52
297737.81628.840.00108.9642,956.68
298737.81630.420.00107.3942,326.27
299737.81631.990.00105.8241,694.27
300737.81633.570.00104.2441,060.70
301737.81635.160.00102.6540,425.55
302737.81636.740.00101.0639,788.80
303737.81638.340.0099.4739,150.47
304737.81639.930.0097.8838,510.54
305737.81641.530.0096.2837,869.01
306737.81643.130.0094.6737,225.87
307737.81644.740.0093.0636,581.13
308737.81646.350.0091.4535,934.78
309737.81647.970.0089.8435,286.81
310737.81649.590.0088.2234,637.22
311737.81651.210.0086.5933,986.00
312737.81652.840.0084.9733,333.16
313737.81654.470.0083.3332,678.69
314737.81656.110.0081.7032,022.58
315737.81657.750.0080.0631,364.82
316737.81659.390.0078.4130,705.43
317737.81661.040.0076.7630,044.39
318737.81662.700.0075.1129,381.69
319737.81664.350.0073.4528,717.34
320737.81666.010.0071.7928,051.32
321737.81667.680.0070.1327,383.64
322737.81669.350.0068.4626,714.30
323737.81671.020.0066.7926,043.28
324737.81672.700.0065.1125,370.58
325737.81674.380.0063.4324,696.20
326737.81676.070.0061.7424,020.13
327737.81677.760.0060.0523,342.37
328737.81679.450.0058.3622,662.92
329737.81681.150.0056.6621,981.77
330737.81682.850.0054.9521,298.92
331737.81684.560.0053.2520,614.36
332737.81686.270.0051.5419,928.09
333737.81687.990.0049.8219,240.10
334737.81689.710.0048.1018,550.39
335737.81691.430.0046.3817,858.96
336737.81693.160.0044.6517,165.80
337737.81694.890.0042.9116,470.91
338737.81696.630.0041.1815,774.28
339737.81698.370.0039.4415,075.91
340737.81700.120.0037.6914,375.79
341737.81701.870.0035.9413,673.93
342737.81703.620.0034.1812,970.30
343737.81705.380.0032.4312,264.92
344737.81707.140.0030.6611,557.78
345737.81708.910.0028.8910,848.86
346737.81710.680.0027.1210,138.18
347737.81712.460.0025.359,425.72
348737.81714.240.0023.568,711.48
349737.81716.030.0021.787,995.45
350737.81717.820.0019.997,277.63
351737.81719.610.0018.196,558.02
352737.81721.410.0016.405,836.60
353737.81723.220.0014.595,113.39
354737.81725.020.0012.784,388.36
355737.81726.840.0010.973,661.53
356737.81728.650.009.152,932.87
357737.81730.470.007.332,202.40
358737.81732.300.005.511,470.10
359737.81734.130.003.68735.97
360737.81735.970.001.840.00

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

Questions

How much is a $175,000 mortgage per month?

At 3.00%, a 30-year $175,000 mortgage costs $737.81 a month in principal and interest. Property tax and insurance add about $142.19 a month on a $218,750 home, for about $879.99 in total.

How much income do I need for a $175,000 mortgage?

About $37,714 a year, if housing costs ($879.99 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 $175,000 mortgage?

$90,611 over 30 years at 3.00%. A 15-year loan at 3.00% cuts that to $42,533, but the payment rises to $1,208.52.

What is the payment on a $175,000 mortgage at 2%?

$646.83 a month over 30 years, −$90.97 compared with 3.00%. Total interest would be $57,860.

How much faster is a $175,000 mortgage paid off with $100 extra a month?

Adding $100 to every payment pays the loan off in 24 years 8 months instead of 30 years and saves about $17,794 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.