| End of Prior Universe time frame | Mass (black hole): super massive end of time BH 1.989 × 1041 to about 1044 grams | Number (black holes): 106 to 109 of them usually from center of galaxies |
| Planck era Black hole formation Assuming start of merging of micro black hole pairs | Mass (black hole) 10−5 to 10−4 grams | Number (black holes) 1022 to about 1021, |
| Post Planck era black holes just before the CMBR formation | Mass (black hole) Up to 106 grams per black hole | Number (black holes) 1018 to at most 1020 |