Below, you will find a chart containing the approximate birth years for age listings on the census. Please remember, that before 1850 the census information on age was vague.
| 1790 Census | BORN | 1830 Census | BORN | |
| 16 and Under | Before 1774 | Under 5 | Between 1825-1830 | |
| Under 16 | Between 1774-1790 | 5-10 | Between 1820-1825 | |
| 1800 Census | 10-15 | Between 1815-1820 | ||
| Under 10 | Between 1790-1800 | 15-20 | Between 1810-1815 | |
| 10-16 | Between 1784-1790 | 20-30 | Between 1800-1810 | |
| 16-26 | Between 1774-1784 | 30-40 | Between 1790-1800 | |
| 26-45 | Between 1755-1774 | 40-50 | Between 1780-1790 | |
| 45 and Over | Before 1755 | 50-60 | Between 1770-1780 | |
| 1810 Census | 60-70 | Between 1760-1750 | ||
| Under 10 | Between 1800-1810 | 70-80 | Between 1750-1740 | |
| 10-16 | Between 1794-1800 | 80-90 | Between 1740-1750 | |
| 16-26 | Between 1784-1794 | 90-100 | Between 1730-1740 | |
| 26-45 | Between 1765-1784 | 100 and Over | Before 1730 | |
| 45 and Over | Before 1765 | 1840 Census | ||
| 1820 Census | Under 5 | Between 1835-1840 | ||
| Under 10 | Between 1810-1820 | 5-10 | Between 1830-1835 | |
| 10-16 | Between 1804-1810 | 10-15 | Between 1825-1830 | |
| 16-18 (males only) | Between 1802-1804 | 15-20 | Between 1820-1825 | |
| 16-26 | Between 1794-1804 | 20-30 | Between 1810-1820 | |
| 26-45 | Between 1775-1794 | 30-40 | Between 1800-1810 | |
| 45 and Over | Before 1775 | 40-50 | Between 1790-1800 | |
| 50-60 | Between 1780-1790 | |||
| 60-70 | Between 1770-1780 | |||
| 70-80 | Between 1760-1770 | |||
| 80-90 | Between 1750-1760 | |||
| 90-100 | Between 1740-1750 | |||
| 100 and Over | Before 1740 |
