What is 35 70mm on medium format in full frame?

35-70mm on medium format gives the view of 28-55mm on full frame.

The same view on every common format:

• Medium format (44 x 33) (yours): 35-70mm
• Full frame: 28-55mm
• APS-C: 18-37mm
• APS-C (Canon): 17-35mm
• Micro Four Thirds: 14-28mm
• 1-inch: 10-20mm
• 1/1.3-inch: 7.7-15mm
• 1/1.7-inch: 6-12mm
• 1/2.3-inch: 4.9-9.9mm

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.