What is 18 270mm on canon aps c in full frame?

18-270mm on APS-C (Canon) gives the view of 29-432mm on full frame.

The same view on every common format:

• Medium format (44 x 33): 36-547mm
• Full frame: 29-432mm
• APS-C: 19-288mm
• APS-C (Canon) (yours): 18-270mm
• Micro Four Thirds: 14-216mm
• 1-inch: 11-160mm
• 1/1.3-inch: 8-120mm
• 1/1.7-inch: 6.3-94mm
• 1/2.3-inch: 5.1-77mm

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.