ƒ/Calc is a calculator for photographic formulas. These formulas are at the heart of many interesting questions about photography. None of these formulas are difficult to compute with a scientific calculator, but doing it by hand is slow, tedious and error-prone. The faster you can get an answer, the faster you can get back to shooting. Or, you can take the same time to learn the answer to more questions! When you let ƒ/Calc do the hard work, you gain an intuitive feel for what the results mean, because you can quickly try new input values to see how they affect the result.

To learn more, you can read through the user manual. The manual is also available in printable form. (PDF, 364 KB)

Use It Online for Free

ƒ/Calc is available in several versions, one of which runs right inside your browser. It has all of the core functionality of the desktop version, and there is no charge for using it. You may find that it does everything you need.

Try It on Your Computer

There is also a “local” version of ƒ/Calc which works just like the online version, but it is more powerful. ƒ/Calc Local lets you work with it while you aren’t connected to the Internet. If you’re already carrying a laptop with you on your photography expeditions, why not take ƒ/Calc along?

ƒ/Calc Local also has more features than ƒ/Calc Online. Currently, the main thing the Local version has over the Online version is that it lets you edit the lens and imaging area tables. If you own lenses or cameras ƒ/Calc Online doesn’t know about, this lets you teach ƒ/Calc about them immediately.

As features are added to the Online version, the Local version will get them too, but not always vice versa. There are several features on the wish list already that will only go in the Local version.

ƒ/Calc Local runs on any computer that supports the Adobe® AIR™ runtime. Currently, this is any modern version of Windows back to Windows 2000, and Mac OS X 10.4 and up. Once upon a time, Adobe offered AIR on Linux; it is discontinued now, but you may be able to find old installers that will still work.

Will You Make a Mobile Version?

Perhaps someday. Don’t hold your breath waiting for it.