# GUTCalc Physics Unit Converter — Calculate in natural units

> Physics unit converter and calculator with SI, natural, and CGS unit support. (iPhone/iPad app by Timothy Wiser.)

- Source: https://appshunter.io/ios/app/gutcalc-physics-unit-converter/id1526914857 (this page in markdown: same URL + `.md`)
- Developer: [Timothy Wiser](https://appshunter.io/developer/1526914859)
- Category: Utilities, Reference
- Price: Free with in-app purchases
- Rating: 5.00/5 from 6 App Store ratings · 1 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 3 MB
- Languages: English
- Released: 2020-08-08
- Data updated: 2026-06-04
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/gutcalc-physics-unit-converter/id1526914857/reviews.md

## What is GUTCalc Physics Unit Converter?

GUTCalc is a calculator that understands units. Enter a free-form expression consisting of arithmetic, SI and non-SI units, physical constants (like Planck's constant h or the speed of light c), and functions (like exp, arctan, and cosh) and GUTCalc will work out the answer including any necessary conversions. Natural units are fully supported, and are great for calculations in particle physics and quantum field theory. SI mode is perfect for quick and easy calculations of everyday quantities.

FEATURES:
* Choose from SI and three types of Natural unit modes. In Natural unit mode, various physical constants (such as hbar, c, kb, and eps0) are set to 1. GUTCalc automatically inserts factors of these constants to perform conversions and calculations in Natural units.
* Gaussian CGS (dynes, ergs, esus, and statvolts) and Planck (quantum gravity) units are also supported.
* Multiplication is implied: no need to insert *s everywhere.
* Custom-designed keyboards for quick and easy input of common units, constants, and functions---or switch to the built-in keyboard for free-form input.
* Calculations can extend over many orders of magnitude without overflow. Need to calculate exp(10000)? No problem. (Available on iOS 11+ and 64-bit devices running iOS 10)
* Avoid algebraic errors thanks to GUTCalc's unit checking: inconsistent calculations are flagged in red with an explanatory message.
* Share your results via email or save them in a note using the share feature.
* Physical constants are updated to the latest values recommended by the Particle Data Group 2020 review, CODATA 2018, and the 2019 redefinition of SI base units.
* Suggestions for features and additional constants are welcome.

UPGRADE TO PRO FOR EXTRA FEATURES:
* Create and manage multiple notebooks to keep your calculations organized
* Sync notebooks with iCloud across multiple devices, including the macOS version of GUTCalc
* Share notebooks with collaborators
* Support the development of more pro features in the future

## Key features

- SI, Natural, and CGS unit modes
- Automatic unit conversion
- Physical constants and functions
- Implied multiplication
- Custom keyboards
- Unit checking for algebraic errors
- Share and save results

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| GUTCalc Pro | $2.99 | one-time |


## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/gutcalc-physics-unit-converter/id1526914857/reviews.md

### 5/5 — Absolutely a must have for particle physics

*2020-10-13*

Amazing App! Super useful! Especially for me!

**Developer response:** Thank you, I'm glad you are finding it useful!

## Frequently asked questions about GUTCalc Physics Unit Converter

### What are the different unit modes available in GUTCalc?

GUTCalc offers SI units for everyday calculations, three types of Natural unit modes where physical constants are set to 1, and also supports Gaussian CGS and Planck units for specialized physics calculations.

### How does GUTCalc help avoid algebraic errors?

GUTCalc features built-in unit checking. If a calculation is inconsistent, it will be flagged in red with an explanatory message, helping users identify and correct algebraic mistakes.

### Can GUTCalc handle very large or small numbers?

Yes, GUTCalc is designed to perform calculations that extend over many orders of magnitude without overflow. For example, it can handle calculations like exp(10000).

### What physical constants are included in GUTCalc?

The physical constants in GUTCalc are updated to the latest recommended values, including those from the Particle Data Group 2020 review and CODATA 2018.

### What are the benefits of upgrading to GUTCalc Pro?

Upgrading to Pro allows you to create and manage multiple notebooks for organized calculations, sync notebooks across devices with iCloud, and share notebooks with collaborators.

### On which devices can I use GUTCalc?

GUTCalc is available for Mac, iPhone, iPad, and iPod. It requires iOS 11+ and 64-bit devices running iOS 10 or later for certain advanced features.

### How often is GUTCalc updated?

The app was last updated on March 26, 2024, indicating active development and support for the latest features and bug fixes.

### What is the user sentiment for GUTCalc?

Based on the available rating, GUTCalc has received overwhelmingly positive feedback, with a perfect 5.0 stars from 6 ratings.

## Version history (last 5 releases)

### 1.2.1 — 2024-03-26

* Fixed a bug where, sometimes, SI units would not show up in results.
* Automatically add an appropriate SI prefix when it simplifies the result (SI and Natural modes only).

### 1.2 — 2022-11-01

Fixed some rare bugs when dealing with fractional powers of units; ending support for iOS 10-12 due to toolchain limitations.

### 1.1 — 2021-05-10

NEW: Cloud syncing and collaboration for Pro users

### 1.0.1 — 2020-11-11

NEW FEATURES:
* Free, limited version
* Upgrade to Pro to manage calculations across multiple notebooks

Changes in 1.0.1:
* Fixed a minor bug when deciding whether or not to (politely) request a review

### 1.0 — 2020-11-08

NEW FEATURES:
* Free, limited version
* Upgrade to Pro to manage calculations across multiple notebooks

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## Related topics

[gutcalc physics unit converter](https://appshunter.io/ios/topics/gutcalc-physics-unit-converter)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-04.*