Free Alternative to Soulver

Numi is still the default free-leaning natural language calculator people compare with Soulver. You type mixed words and math—'$20 in euro - 5% discount', date math, unit conversions—and answers appear inline. There are Mac, Windows, and Linux builds, plus a CLI direction from the open GitHub project. As of August 2026 Numi remains available from numi.app without a Soulver-sized one-time fee for basic use; pro/paid unlocks exist depending on platform packaging. Honest gap: Soulver 4's multi-device sheets, answer column refinement, tags, trip planning, and agent-friendly tooling are simply more mature. Numi is great for daily conversions and freelancers who refuse another paid utility; it is not a full Soulver clone.

Raycast is technically an application launcher designed to replace Spotlight. The built-in calculator engine is shockingly capable. I actually stopped launching dedicated calculator apps entirely once I learned Raycast's syntax. You hit Command-Space and type "100 GBP in USD" or "time in Tokyo". It spits out the answer instantly.

The parsing engine handles complex unit conversions better than anything else I tested. Version 1.62 added even better natural language recognition. The major downside is the lack of a multi-line notepad interface. You cannot link variables together or save a sheet of calculations for later. It only does one math problem at a time. If you need to calculate freelance taxes with five different line items, Raycast falls apart. For quick one-off queries, it is absolutely unbeatable. It lives in your system memory anyway as a launcher. You get the calculator functionality for free without running an extra background process.

Qalculate is an open-source powerhouse. I will be completely honest. The GTK user interface looks terrible on a Mac. It feels like a Windows 95 application ported as an afterthought. You have to ignore the visual design entirely. Once you do, you find the most capable calculation engine on the planet.

I threw bizarre physics units and obscure currency pairs at version 5.0.0. It solved everything instantly. It handles natural language parsing just like Soulver. It also supports symbolic algebra, calculus, and matrix operations. The error messages are actually helpful if you mistype a formula. It tells you exactly where the syntax failed. The settings menus are overwhelmingly complex. You can tweak everything from the default currency provider to the exact precision of floating-point numbers. It is complete overkill for calculating a grocery bill. It is absolutely perfect for engineering students who want a free tool.

Parsify takes the exact multi-line notepad concept from Soulver and builds it using web technologies. I usually hate Electron applications. They consume too much memory. Parsify version 2.0 does eat about 150MB of RAM just to sit idle. The interface is remarkably clean though. It looks modern and fits well alongside tools like Notion or Slack.

The defining feature is the plugin system. You can write custom JavaScript plugins to extend the math engine. The core application handles basic arithmetic, percentages, and unit conversions perfectly. The free tier restricts how many plugins you can install. The developer limits some advanced functionality to a paid version. I found the free version perfectly adequate for tracking monthly expenses. The text editing feels slightly sluggish compared to native apps like Numi. You notice a tiny delay when typing fast. It remains a very solid alternative if you prefer a modern web-style aesthetic.

SpeedCrunch ignores the notepad metaphor entirely. It focuses strictly on speed and history. I installed version 0.12 and immediately appreciated the snappy Qt-based interface. You type your equation at the bottom prompt. The result appears in the scrolling history list above.

It does not support natural language parsing. You cannot type "20% of 50". You have to type "50 * 0.2". This makes it a poor replacement for the casual Soulver user. It shines when you need to do rapid algebraic calculations without touching your mouse. The auto-completion engine is fantastic. You start typing a function name and it suggests the rest immediately. You can define custom variables and reuse them throughout your session. It lacks live currency conversions completely. This is strictly a math tool. I keep it installed for when I need to crunch raw numbers fast.

Fend is a command-line tool. I know terminal applications scare some people away. You should give this one a chance. The developer built it in Rust. It launches instantly and uses almost zero system resources. I tested version 1.4.0. The unit conversion engine is spectacular.

You can type "5 miles in km" or "100 celsius in fahrenheit". It parses the text and returns the answer immediately. It handles date math beautifully. You can ask for "today + 3 weeks". The major drawback is the lack of a graphical interface. You have to open Terminal or iTerm to use it. There is no way to save a sheet of calculations. It operates purely as a read-eval-print loop. I alias it to a simple terminal command. It serves as my primary quick-math tool when I am already working in a command-line environment.

Insect is another terminal-based calculator. It focuses heavily on physical units and strict mathematical rules. I found it slightly more rigid than Fend. It requires exact syntax for conversions. You cannot be lazy with your phrasing.

The tradeoff for this strictness is incredible accuracy. It understands complex compound units like "kilogram meter per second squared". It will catch your errors if you try to add incompatible units together. It throws a clear error if you attempt to add seconds to meters. The project seems largely abandoned. The GitHub repository has not seen a major update since 2021. The core math engine still works perfectly on modern macOS versions. It lacks currency support completely. I recommend this specifically for students dealing with physics or chemistry homework where unit tracking is critical.

Kalker sits comfortably between simple arithmetic tools and complex programming languages. I installed version 2.1.0. It offers a terminal interface with beautiful syntax highlighting. The standout feature is the ability to define custom mathematical functions on the fly.

You can type "f(x, y) = x * y + 10" and then call that function later in your session. It handles basic calculus and trigonometry easily. The application is written in Rust, ensuring rapid response times. It does support some natural language elements, but it leans heavily into traditional math notation. The error messages can get highly technical. If you mistype a complex derivative, the output looks like a compiler error. It remains a fantastic free alternative for users who find traditional calculators too limiting but do not want to write Python scripts for simple math.

I have to include Spotlight. Every Mac comes with it built-in. You press Command-Space and type your math problem. Apple has slowly improved the underlying engine over the last few macOS releases. I tested it extensively on macOS Sonoma.

It handles basic currency conversions and unit math surprisingly well. You can type "500 EUR in USD" and get a quick answer. The problem is the user experience. The result disappears the second you click away. You cannot chain calculations together. The currency rates often lag a few hours behind real-time market data. I found it frustrating for anything beyond a single addition problem. It costs absolutely nothing. You do not have to install Homebrew to use it. For a large portion of casual users, Spotlight is the only alternative they actually need.