You asked
What is 150 400mm on micro four thirds in full frame?
150-400mm on Micro Four Thirds gives the view of 300-800mm on full frame.
The same view on every common format:
- Medium format (44 x 33): 380-1013mm
- Full frame: 300-800mm
- APS-C: 200-533mm
- APS-C (Canon): 188-500mm
- Micro Four Thirds (yours): 150-400mm
- 1-inch: 111-296mm
- 1/1.3-inch: 83-222mm
- 1/1.7-inch: 65-174mm
- 1/2.3-inch: 54-143mm
Crop factors are by the sensor diagonal, rounded as they're usually quoted; a format with a different shape (4:3 against 3:2) frames a little differently across the width. More in the focal length converter.
Computed from the sensor sizes, not written by a model.