The Best Free Calculators

Online math solver, equation editor and database, graphing calculator and science/engineering problem helper.

Soulver is a smart notepad with a built-in calculator. It gives instant answers to any calculations it finds in your text. It's a better way to work stuff out than with a traditional calculator, and a more lightweight tool for quick calculations than a spreadsheet.

A playground for ideas involving math

Soulver is great as a simple calculator replacement. But it really shines when you use it to explore different scenarios and experiment with numbers. You can you use words and numbers alongside each other and you almost never encounter an error. And all your work is automatically saved for you so you can reference it later.

A better math machine

With Soulver you can see and edit all your calculations, all the time. Unit conversions, including live real-world and cryptocurrencies are built-in. Use headings, labels and comments to give your notes structure, and enjoy automatic formatting features and tasteful syntax coloring.

Take a load off your brain

Soulver comes with a set of natural language functions that make it easy to do common operations. For example, working with dates, times, percentages and proportions is easier than ever. And we're always thinking of new ways to make common tasks involving numbers more natural for the human brain.

An easy to use, versatile tool

Soulver comes with a stack of handy features for doing multi-step calculations. For instance, you can reference previous lines, kind of like a spreadsheet. And like a programming language, you can assign names to numbers and use them as variables in your calculations.
A total at the bottom automatically adds up all your line, and you can make subtotals of specific lines.

SpeedCrunch is a free, fast, high precision open source algebraic calculator with an intuitive interface and a extensive list of features, including:
Unlimited Variables,
Syntax Highlighting,
Functions, with 'Automagic' Completion,
50 Decimal Precision,
Input History
and more...

Omni Calculator is a web/mobile calculator that solves concrete problems such as mortgage payment, gross margin, body mass index, break-even point, etc. It's very user-friendly, flexible and usable on web, mobile and as an embeddable web widget.

CalcTape is a revolutionary new kind of pocket calculator. With CalcTape, also extensive calculations remain clearly structured. CalcTape makes the arithmetic process visible - you can generate intermediate results and subsequently correct or change all numbers and operations.

CalcTape for Windows - details:

• Enter many calculation terms in one turn and still keep an overview - like on an adding machine.
• Change any term afterwards and CalcTape will refresh the whole calculation automatically.
• Use intermediate results to check and structure your calculation.
• Comment your calculation terms, to give sense and context to it.
• Save your calculations into files. Open the files later and you can change the calculations. CalcTape will refresh the whole calculation automatically again and again.
• Use your existing CalcTape files as templates. Do similar calculations and play different scenarios.
• Use the programmable buttons e.g. for fast TAX calculations.
• CalcTape masters the four basic arithmetical operations, exponentials, and percentage calculations.
• CalcTape for Windows requires Windows XP, Windows Vista (x86 and x64) or Windows 7 (x86 and x64).

Extended functionality of the Pro and Enterprise version:

• Scratchpad for every-day calculations is being saved automatically.
• Put calculations side by side for comparison.
• Work with variables and generate "speaking" calculations.
• Define as many programmable keys as you like.
• Use parentheses and trigonometry when defining variables.
• And much more ...

OpalCalc is a brand new type of calculator for the PC. As easy to use as Notepad or a word processor, OpalCalc allows natural language in the sum and multi-line support so you can go back and adjust your previous calculations on the fly.

For years, PC calculators have been trying to copy handheld calculators in both functionality and appearance. OpalCalc sets out to disregard previous conceptions, and instead we considered how a calculator should behave with a full keyboard in mind. The result is simplicity itself, but with almost spreadsheet-like capability.

OpalCalc features include percentages, currency conversion, custom functions/variables, excellent documentation, colour coding, lightweight size, configurable GUI, hundreds of measures and functions, and lots more. The full version can be obtained with a donation of any amount (even a few pence). There is no time limit in the 'lite version', just a 5 line limit which is very useful for most purposes.

Microsoft Mathematics is a desktop graphing calculator that can help you visualize and see mathematical concepts as you’ve never seen them before. Microsoft Mathematics includes ink handwriting support to recognize hand-written problems.

Qalculate! is a multi-purpose cross-platform desktop calculator. It is simple to use but provides power and versatility normally reserved for complicated math packages, as well as useful tools for everyday needs (such as currency conversion and percent calculation). Features include a large library of customizable functions, unit calculations and conversion, symbolic calculations (including integrals and equations), arbitrary precision, interval arithmetic, plotting, and a user-friendly interface (GTK+ and CLI).

Calculator provides simple and advanced mathematical functions in a beautifully designed app.