PCalc

The current version is 4.5.7

Best Calculator EVER. I use it both on my Mac and iPhone. I love the themes, the interface customization. I love that you can customize the keys to perform actions you want. I love the unit conversions. I love the ability to do Standard or Reverse Polish Notation calculations. PCalc is as easy to use or as heavy duty as you want. Highly recommended. The only calculator worth buying.

one of the best apps I've ever bought

I love this cal since the beginning as a MacOS 9 user. However, now that the world is 64bits everywhere, it needs to support numbers bigger than 48bits.

I love this calculator! Now in version 4 there were many new items added which makes it more compatible to the versions in iOS 7. It is my calculator since the beginning and so I realized the changes. The big layouts are wonderful for an old guy like me and the themes are very good. I didn't realize any big faults and the saved constants are a big help for me. It is fast, stable and worked in every OS X I ever used. Great! The number of digits could be a little bigger, but 15 is more than enough for the daily use I think. A big thank you to the developer and his continuous maintenance. Danke!

PCalc 20th Anniversary sale! Only $0.99 in the Mac and iOS app stores until December 29th: http://www.pcalc.com/mac_app_store/pcalc http://www.pcalc.com/itunes_store_link/pcalc

As a long-time user of DragThing, I expected PCalc to be an equally superb application, with support to match. I wasn't disappointed. I loved KoalaCalc, but I prefer PCalc, and it's worth every penny of the modest shareware fee.

Great looking, intuitive, powerful and easy to use app. Delighted to see this updated for Retina today.

Over many years, and many trials, this is the one calculator I come home to. It gives me what I need right there. It has earned a place in my Dock. The iOS version was the 1st app i bought for my iPad. Insanely great. Even worse, the developer is very responsive!

Simply the best. Strong support, updated regularly, stable, comprehensive functions, RPN mode, and looks great.

I've been using and enjoying PCalc for years, and I love the new icon :)

Could not ask for a more convenient Calculator.

I liked Koala Calc, mentioned by the previous reviewer. I don't recall the specifics of why I stopped using it. I do recall that the latest version is from 2005. These days I use PCalc. Great features, excellent support, and it is maintained regularly.

The calculator that i prefer is Koloa Calc. It is also free and the numeric entry is easier for me. http://www.macropodsoftware.com/

I tried this out quite a few years ago and didn't care for it (although I can't remember why). I tried it out recently and didn't care for the appearance, but I found that it was the only RPN calculator that works the way I like. I was looking for a replacement for J.M. Baker's 'RPN Calculator' which isn't developed anymore. I played around and found that the appearance, size, etc. are highly customizable, so now it looks great. PCalc has a combination of features that I couldn't find anywhere else--RPN, stack view, keyboard shortcuts that I like... I initially thought $19 was high for a calculator, but I soon found I couldn't live without it and registered. I took advantage of the offer to get the iPhone/iPod version too, for only $.99 more than the price of the desktop version. I keep finding features (like tons of physics unit conversions, for example) that are saving me a lot of time. It appears to have outstanding support as well. Best app I've (re)discovered in a long time.

This is only a comment in general not a swipe at this particular developer. Why does the mac app cost $20 and the iphone app is only $10 ? I am starting to wonder if all the mac apps are over priced.

This was the first piece of shareware I installed on my Mac SE back in the 1980s. It just gets better and better with every upgrade. James, you are a great contributor to the ease and enjoyment of using a Mac. DragThing and pCalc are absolutely the tops in their fields.

Seems to have lots of functionality, but is completely lacking in any useful instructions. It would be nice to have a desktop calculator to handle simultaneous and quadratic equations, but I cannot figure out how to use the functions. The conversions and constants are great, but whout knowing how to use the "advanced" features I cannot see how this is any more use than Apples FREE calculator.

Wow, I have never ever seen such a wonderful calculator! Why has no one every came up with a perfect calendar as this? Awesome! The developer must never sleep because he responds so quickly! Don't miss out!

Easy to use, nice interface, but Magic Number Machine has more features and it is free http://www.macupdate.com/info.php/id/13214