Please use this tool cautiously. The close focus when using a macro extension tube can vary based on unique design of the taking lens. The results produced by this tool can be +/- 10%. This means that a distance can be off by several inches in certain cases. Please contact us if you have any issues using this tool or have any recommendations for updates.
Macro Extension Tube Calculator
New Close Focus Distance:
This is the new focus distance from the film plane. Be sure to account for the physical length of your lens. If the close focus is 6" and your lens is 7" long, this will NOT work.
New Far Focus Distance:
This is the new focus distance from the film plane. Be sure to account for the physical length of your lens.
New Total Focus Range:
Imperial to Metric Conversion
If needed, convert feet and inches to millimeters to use the calculator above.
(Use feet in decimal format or combine feet and inches.)
Distance in mm: