DOFMaster LE makes it easy. Tap three times to set f-stop, focal length, and focus distance. Read the near focus distance, far focus distance, and the hyperfocal distance.

DOFMaster for iPhone / iPod touch for depth of field calculations on your phone. Get the app on the iTunes App Store or use the iPhone web app.

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.