Convert Megatons to Gigatons
Convert Megatons (Mt) to Gigatons (Gt) instantly and accurately.
Conversion Formula
Gt = Mt × 0.001
About Megatons
A megaton (Mt) equals one million metric tonnes (10⁹ kg). Nuclear weapon yields are measured in megatons of TNT equivalent: the largest weapon ever detonated, the Soviet Tsar Bomba tested in 1961, had a yield of approximately 50 Mt TNT and produced a fireball 8 km in diameter. Annual global CO₂ emissions are reported in gigatons (Gt), but regional emissions data and specific industrial sectors are quoted in megatons. The Chicxulub asteroid impact that caused the Cretaceous-Paleogene mass extinction released energy equivalent to roughly 100 million Mt of TNT.
About Gigatons
A gigaton (Gt) equals one billion metric tonnes (10¹² kg). It is the standard unit for planetary-scale mass measurements and global environmental budgets. Annual human CO₂ emissions are approximately 37 Gt CO₂; Earth's atmosphere contains roughly 5,480 Gt of air; Antarctic ice sheet mass is around 26,500,000 Gt of ice. Climate scientists report ice sheet mass balance changes in gigatons per year - the Greenland ice sheet loses approximately 280 Gt of ice annually due to climate change.
Quick Reference Table
| Megatons (Mt) | Gigatons (Gt) |
|---|---|
| 1 Mt | 0.001 Gt |
| 2 Mt | 0.002 Gt |
| 5 Mt | 0.005 Gt |
| 10 Mt | 0.01 Gt |
| 25 Mt | 0.025 Gt |
| 50 Mt | 0.05 Gt |
| 100 Mt | 0.1 Gt |