Convert Millennia to Megayears
Convert Millennia (ka) to Megayears (Ma) instantly and accurately.
Conversion Formula
Ma = ka × 0.001
About Millennia
A millennium (1 ka) = 1,000 Gregorian years ≈ 3.156 × 10¹⁰ s. Standard unit in archaeology and Quaternary geology: Neolithic transition ~10-12 ka BP; Last Glacial Maximum ~21 ka BP; Homo sapiens leaving Africa ~60-70 ka BP. Milankovitch cycles include the 41 ka obliquity and ~100 ka eccentricity cycle. EPICA Antarctic ice core spans ~800 ka. Precession completes ~26 ka. 1 ka = 1,000 yr.
About Megayears
A megayear (1 Ma) = 10⁶ yr ≈ 3.156 × 10¹³ s - the timescale of geology and tectonic evolution. The K-Pg mass extinction at 66.0 Ma; Cambrian explosion ~538.8 Ma; Great Oxygenation Event ~2,400 Ma. Plate motion at 2-10 cm/yr = 200-1,000 km per Ma (Atlantic ~3,000 km wider since Pangaea rifting ~200 Ma ago). Background extinction rate measured in extinctions per million species-years. 1 Ma = 10⁶ yr.
Quick Reference Table
| Millennia (ka) | Megayears (Ma) |
|---|---|
| 1 ka | 0.001 Ma |
| 2 ka | 0.002 Ma |
| 5 ka | 0.005 Ma |
| 10 ka | 0.01 Ma |
| 25 ka | 0.025 Ma |
| 50 ka | 0.05 Ma |
| 100 ka | 0.1 Ma |