What is 15 45mm on aps c in full frame?

15-45mm on APS-C gives the view of 22-68mm on full frame.

The same view on every common format:

• Medium format (44 x 33): 28-85mm
• Full frame: 22-68mm
• APS-C (yours): 15-45mm
• APS-C (Canon): 14-42mm
• Micro Four Thirds: 11-34mm
• 1-inch: 8.3-25mm
• 1/1.3-inch: 6.2-19mm
• 1/1.7-inch: 4.9-15mm
• 1/2.3-inch: 4-12mm

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.