Cautions:

TMRCA (time to most recent common ancestor) calculations are only estimates; they do not specify precisely when the ancestor lived.

And, markers matching vs. markers compared is a crude measure of the degree of match. Which markers mismatch can be more important than how many mismatch.

Reading the tables:

  1. Find the degree of match, stated in number of markers matching vs. number compared
  2. Read down that column until finding the desired cumulative probability for the common ancestor.
  3. Look at the left-hand column (T.E.); this is the maximum number of generations for this degree of match
  4. The column just to the right (~ Generations) is the rough estimate number of generations between living descendants and the common ancestor.

Color coding

Beige cells mark ~50% probability; the odds are even that
(a) the common ancestor lived within that time span or (b) earlier.
Blue cells mark ~80% probability; the odds are 4 out of 5 that
the common ancestor lived within that time span.
Green cells mark ~90% probability; the odds are 9 out of 10 that
the common ancestor lived within that time span.

37-marker Table

T.E. ~
Gene-
rations
Number Matching Markers
37/3736/3735/3734/3733/3732/3731/37
Cumulative Probabilities
1111.5% 1.3% 0.1% 0.0% 0.0% 0.0% 0.0%
21-221.7% 3.6% 0.3% 0.0% 0.0% 0.0% 0.0%
31-230.7% 6.6% 0.9% 0.1%0 .0% 0.0% 0.0%
42-338.6%10.2%1.7% 0.2% 0.0% 0.0% 0.0%
52-345.7%14.2%2.9% 0.4% 0.0% 0.0% 0.0%
62-351.9%18.4%4.3% 0.8% 0.1% 0.0% 0.0%
73-457.5%22.8%6.1% 1.2% 0.2% 0.0% 0.0%
83-462.4%27.2%8.2%1.9% 0.3% 0.0% 0.0%
9466.7%31.6%10.5% 2.7% 0.5% 0.1% 0.0%
10570.5%36.0%13.1% 3.6% 0.8% 0.1% 0.0%
11573.9%40.2%15.8% 4.8% .2% 0.2% 0.0%
12676.9%44.3%18.7% 6.1% 1.6% 0.3% 0.1%
13679.6%48.3%21.7% 7.6% 2.1% 0.5% 0.1%
14781.9%52.0%24.9% 9.3% 2 .8% 0.7% 0.1%
15784.0%55.6%28.0%11.1% 3.6% 0.9% 0.2%
16885.8%59.0%31.2%13.1% 4.4% 1.2% 0.3%
17887.5%62.2%34.4%15.2% 5.4% 1.6% 0.4%
18988.9%65.2%37.6%17.4% 6.6% 2.1% 0.5%
19990.2%68.0%40.8%19.7% 7.8% 2.6% 0.7%
201091.3%70.6%43.9%22.1% 9.1% 3.2% 0.9%
211092.3%73.0%47.0%24.6%10.6% 3.8% 1.2%
221193.2%75.3%49.9%27.1%12.2% 4.6% 1.5%
231194.0%77.4%52.8%29.7%13.9% 5.4% 1.8%
241294.7%79.3%55.6%32.3%15.6% 6.4% 2.2%
251295.3%81.1%58.3%34.9%17.5% 7.4% 2.7%
261395.8%82.8%60.9%37.6%19.4% 8.5% 3.2%
271396.3%84.3%63.4%40.2%21.4% 9.7% 3.8%
281496.7%85.7%65.7%42.8%23.5%11.0% 4.4%
291497.1%86.9%68.0%45.3%25.6%12.3% 5.1%
301597.4%88.1%70.1%47.8%27.8%13.8% 5.9%
311597.7%89.2%72.1%50.3%30.0%15.3% 6.7%
3216>98%90.2%74.1%52.7%32.2%16.9% 7.6%
331691.1%75.9%55.1%34.5%18.5% 8.6%
341791.9%77.6%57.4%36.7%20.3% 9.7%
351792.7%79.2%59.6%39.0%22.0%10.8%
361893.3%80.7%61.8%41.2%23.8%12.0%
371894.0%82.1%63.9%43.4%25.7%13.2%
381994.5%83.4%65.9%45.7%27.6%14.5%
391995.0%84.7%67.8%47.8%29.5%15.9%
402095.5%85.8%69.7% 50.0%31.4%17.3%
412095.9%86.9%71.4%52.1%33.4%18.8%
422196.3%87.9%73.1%54.2%35.4%20.3%
432196.7%88.9%74.8%56.2%37.4%21.9%
442297.0%89.7%76.3%58.2%39.4%23.5%
452297.3%90.5%77.8%60.2%41.4%25.1%
462397.6%91.3%79.2%62.1%43.4%26.8%
4723>98%92.0%80.5%63.9%45.3%28.5%
482492.6%81.7%65.7%47.3%30.2%
A typical genealogical time frame spans only the
most recent 24 generations, ~ 48 Transmission Events.
492493.2%82.9%67.4% 49.2%32.0%
502593.8%84.1%69.1%51.1%33.8%
512594.3%85.1%70.7%53.0%35.5%
522694.8%86.1%72.2%54.8%37.3%
532695.2%87.1%73.7%56.7%39.1%
542795.6%87.9%75.1%58.4%40.9%
552896.0%88.8%76.5%60.2%42.7%
562896.3%89.6%77.8%61.9%44.5%
572996.6%90.3%79.1%63.5%46.3%
582996.9%91.0% 80.2%65.2%48.0%
593097.2%91.6%81.4%66.7%49.8%
603097.4%92.2%82.5%68.3%51.5%
613197.6%92.8%83.5%69.7%53.2%
6231>98%93.3%84.5%71.2%54.9%
633293.8%85.4%72.5%56.5%
643294.3%86.3%73.9%58.2%
653394.7%87.2%75.2%59.7%
663395.1%88.0%76.4%61.3%
673395.5%88.7%77.6%62.8%
683495.8%89.4%78.8%64.3%
693496.1%90.1% 79.9%65.8%
703596.4%90.7%80.9%67.2%
713596.7%91.3%81.9%68.6%
723697.0%91.9%82.9%69.9%
733697.2%92.4%83.8%71.3%
743797.4%92.9%84.7%72.5%
753797.6%93.4%85.6%73.7%
7638>98%93.9%86.4%74.9%
773994.3%87.2%76.1%
783994.7%87.9%77.2%
794095.0%88.6%78.3%
804095.4%89.3%79.3%
814195.7% 89.9%80.3%
824196.0%90.5%81.3%
834296.3%91.0%82.2%
844296.5%91.6%83.1%
854396.8%92.1%83.9%
864397.0%92.6%84.8%
874497.2%93.0%85.5%
884497.4%93.5%86.3%
894597.6%93.9%87.0%
9045>98%94.3%87.7%
914694.6%88.3%
924695.0%89.0%
934695.3%89.6%
944795.6% 90.1%
954795.9%90.7%
964896.1%91.2%
974896.4%91.7%
984996.6%92.2%
994996.9%92.6%
1005097.1%93.0%
1015097.3%93.4%
1025197.4%93.8%
1035197.6%94.2%
10452>98%94.5%
1055394.8%
1065395.2%
1075495.4%
1085495.7%
1095596.0%
1105596.2%
1115696.5%
1125696.7%
1135796.9%
1145797.1%
1155897.3%
1165897.4%
11759 97.6%
11859       >98%
11960       
12060       

67-marker Table

67-marker matches yield greater precision to TMRCA estimates.

T.E.   Number Matching Markers
67/6766/6765/6764/6763/6762/6761/67
Cumulative Probabilities
1119.8% 3.9% 0.4% 0.0% 0.0% 0.0% 0.0%
21-235.7%10.1% 1.8% 0.2% 0.0% 0.0% 0.0%
31-248.5%17.6% 4.2% 0.7% 0.1% 0.0% 0.0%
42-358.7%25.7% 7.6% 1.7% 0.3% 0.0% 0.0%
52-366.9%33.7%12.0% 3.3% 0.7% 0.1% 0.0%
6 73.5%41.5%17.0% 5.4% 1.4% 0.3% 0.1%
7 78.7% 48.8%22.5% 8.1% 2.4% 0.6% 0.1%
8 82.9%55.5%28.3%11.5% 3.8% 1.1% 0.2%
9 86.3%61.5%34.2%15.2% 5.6% 1.7% 0.5%
10 89.0%66.9%40.0%19.4% 7.8% 2.6% 0.8%
11 91.2%71.7%45.7%23.9%10.4% 3.8% 1.2%
12 93.0%75.8%51.2%28.6%13.4% 5.3% 1.8%
13 94.4%79.5%56.3%33.4%16.7% 7.1% 2.6%
14 95.5%82.6%61.1%38.3%20.3% 9.3% 3.7%
15 96.4%85.3%65.6%43.1%24.2%11.7% 4.9%
16 97.1%87.6%69.6% 47.8%28.2%14.4% 6.4%
17 97.7%89.6%73.3%52.3%32.3%17.3% 8.1%
18 >98%91.2%76.6%56.6%36.5%20.5%10.1%
19 92.7%79.6%60.7%40.7%23.8%12.3%
20 93.9%82.2%64.6%44.8%27.3%14.7%
21 94.9%84.6%68.2% 48.9%31.0%17.4%
22 95.7%86.7%71.5%52.8%34.7%20.2%
23 96.4%88.5%74.6%56.6%38.4%23.2%
24 97.0%90.1%77.4%60.3%42.1%26.3%
25 97.5%91.5% 80.0%63.7%45.8%29.5%
26 >98%92.7%82.3%67.0% 49.4%32.8%
27 93.8%84.4%70.1%53.0%36.2%
28 94.7%86.2%73.0%56.4%39.6%
29 95.5%87.9%75.6%59.7%43.0%
30 96.1% 89.4%78.1%62.9%46.3%
31 96.7%90.8% 80.3%65.9%49.6%
32 97.2%91.9%82.4%68.8%52.9%
33 97.6%93.0%84.3%71.5%56.1%
34 >98%93.9%87.6%74.0%59.1%
35 94.7%89.0%76.4%62.1%
36 95.4% 90.3%78.6%64.9%
37 96.0%91.4% 80.7%67.6%
38 96.6%92.4%82.5%70.1%
39 97.1%93.3%84.3%72.6%
40 97.5%94.1%85.9%74.9%
41 97.8%94.9%87.3%77.0%
42 >98%95.5%88.7%79.0%
43 96.1% 89.9%80.9%
44 96.6%91.0%82.6%
45 97.0%92.0%84.3%
46 97.4%92.9%85.7%
47 97.4%93.7%87.1%
48 97.7%94.4%88.4%
A typical genealogical time frame spans only the
most recent 24 generations, ~ 47 Transmission Events.
49 >98%95.0% 89.5%
50 95.6%90.6%
51 96.1%91.6%
52 96.6%92.4%
53 97.0%93.2%
54 97.4%94.0%
55 97.7%94.6%
56 >98%95.2%
57 95.7%
58 96.2%
59 96.6%
60 97.0%
61 97.4%
62 97.7%