These equivalents are based on the International Standard Atmosphere and promulgated by ICAO:
| mbar (hPa) | Nominal Altitude (ft to nearest 1000 ft; metres to nearest 100 m) |
| 100 | 53,000 ft / 16,200 m |
| 200 | 39,000 ft / 11,800 m |
| 250 | 34,000 ft / 10,400 m |
| 300 | 30,000 ft / 9,200 m |
| 400 | 24,000 ft / 7,200 m |
| 500 | 18,000 ft / 5,600 m |
| 600 | 14,000 ft / 4,200 m |
| 700 | 10,000 ft / 3,000 m |
| 850 | 5,000 ft / 1,500 m |
For full details, see this article. The article also has the definitions of QFE, QNH, QFF and QNE.