Depth of Field Calculator
Use the actual focal length of the lens for depth of field calculations. When you select a camera, the calculator will automatically adjust for any "focal length multiplier" or "field of view crop."

DOFMaster
Use DOFMaster to print depth of field scales to take into the field. Rotate the dial to set the focus distance on the scale, and quickly read the near focus distance, far focus distance, and the hyperfocal distance.