Excalibur

Excalibur for Windows 32-bit version is a freeware full featured RPN-only calculator. This is a serious calculator for serious users. Excalibur takes up a small amount of resources for all it does so well.

Free Windows

Calculator++

A multipurpose calculator app with slick and intuitive user interface. Access additional features from the main screen of the app using gestures. It has a big variety of built-in functions and supports adding new user-defined functions.

Free Open Source Android Android Tablet

Precise Calculator

Programmable scientific calculator which has more than 150 mathematical functions and all of them return as many digits as you need. It can calculate with real numbers, complex numbers, fractions, vectors, matrices.

Free Open Source Windows

Arithmate Pro Calculator

A modern, scientific calculator that is easy to use. While other calculators display only one number at a time, this one shows you the whole expression you are inputting, leading to a much more user friendly experience.

Commercial Android

MyScript Calculator

With MyScript Calculator, perform mathematical operations naturally using your handwriting.

Free Android iPhone Android Tablet iPad

Omni Calculator

Omni Calculator is a web/mobile calculator that solves concrete problems such as mortgage payment, gross margin, body mass index, break-even point, etc.

Free Android iPhone iPad Web

ESBCalc

ESBCalc is a Freeware Scientific Calculator for Windows with Infix Notation, Brackets, Scientific Functions (Trigonometric, Hyperbolic, Logarithmic - including Base 10, Base 2 & Natural - plus more), Memory, Paper Trail, Result History...

Freemium Windows

XCALC

XCALC is my little RPN calculator completely free to use, and still downloadable. XCALC is now a DEAD project. No work has been done on this project since 2012, and nothing more will be done either.

Free Open Source Windows Linux

Moffsoft FreeCalc

Moffsoft FreeCalc is the ideal replacement for your standard Windows calculator - with adjustable size, visible memory value and digit groupings, this free calculator...

Freemium Windows

Reor

Reor is a powerful calculator blended into perfection with a winsome interface. Reor is freeware, licensed under GNU General Public License (Version 3). Reor has a wide...

Free Personal Windows

Calculator Plus

Calculator Plus is a nice addition to hundreds of Calculator apps but with unique idea and innovative and user friendly designed buttons. A sound and smart person...

Free Android

eCalc Scientific Calculator

An easy to use scientific calculator with many advanced features to help you solve algebra, trigonometry, and engineering math problems. The calculator comes with six...

Commercial Mac OS X Windows

Calculate

A math expression calculator with persistent memory for variables and functions. Any JavaScript expression can be evaluated. - Click the C button to clear the output...

Free Mac OS X

ECW Expression Calculator

ECW Expression Calculator is an advanced expression calculator with the following features: * display result as decimal/hex/bin/oct/exponential * standard and...

Free Windows

Calc98

Calc98 is a small but very powerful scientific calculator, with lots of features: Version 5.3 (totally free) # RPN # Base-n, hex, octal and binary modes #...

Free Windows Windows Mobile

Engineering Calculator

Pocket PC calculator for scientific and engineering purposes. This calculator is very bright and easy to use, supports more than 50 functions. The Engineering...

Free Personal Windows Mobile

errProof

The website has a lot of useful and unique tools.

Free Web

Online Terminal Calculator

Online terminal based calculator, it is one of the most productive calculator in online, it uses terminal based approach instead of traditional push button based.

Free Web

Ruvenss Calculator

Simple yet very effective calculator with print capabilities and log registration.

Free Mac OS X Windows Linux Chrome OS