Convert GRB to CAL

The quick and simple way to convert your GRB into CAL files is to use a quality piece of software, such as reaConverter.

reaConverter is offline conversion software that supports multiple file formats, including GRB to CAL conversion, along with image editing capabilities.

Download
reaConverter
Convert
GRB to CAL
Online
Convert

How to Convert Multiple GRB Files to CAL?

1. Download and Install reaConverter

reaConverter is quick to download, install and launch. This standalone software is extremely efficient in managing a wide range of batch conversions. reaConverter is incredibly powerful and boasts an extensive variety of features.

reaConverter logo
Install reaConverter

2. Load your GRB files

Start reaConverter and load all the .grb files you intend to convert into .cal. The software supports multiple GRB conversion and processes all files locally on your computer.

Select GRBs from a folder or by drag-and-dropping them directly into the reaConverter window.

Load your GRB files into reaConverter

3. Select CAL as output format

Pick the CAL as output format and choose the destination folder where you want to save new .cal files.

Select CAL as output format

4. Start GRB to CAL conversion

Then simply press Convert button and your conversion will begin in no time!

Screenshot

Once the conversion is complete, you can find your CAL files in the destination folder you selected.

GRB to CAL Converter

reaConverter offers the fastest, simplest solution for converting your GRB files into CAL in seconds - all files processed on your PC for maximum privacy and speed.

Download Free Trial

Do more with your files

Converting GRB files for use in a workflow? reaConverter offers many ways to process files, so you can customize them according to your requirements.

Our range of editing options includes auto-processing options such as auto-rotate, auto-crop, watermarking and more. Change Color Space, copy Metadata, set DPI, manage ICC Profile, control Bit Depth.

Conversion features
Image editing

User Reviews

Average User Rating:
Last updated on May 24, 2025
"This software just works! My old laptop can’t handle Photoshop, but reaConverter flies through conversions without breaking a sweat. Wi-Fi gone? Still strong!"
⭐⭐⭐⭐⭐
Robert Williams
Happy User
"Rare software that actually does it all! Converts anything, beautiful interface, and never lets me down. A must-have!"
⭐⭐⭐⭐⭐
Henry R.
Happy User
"For cross-platform compatibility, JPEG remains the gold standard. reaConverter’s precision conversions ensure perfect results every time, whether for presentations, websites, or client deliverables."
⭐⭐⭐⭐⭐
Paul Baker
Happy User
"Your solution was buried deeper in search results than it should be. After struggling with unclear alternatives, I found your guides — finally, instructions that made sense for a first-time user like me. Excellent work!"
⭐⭐⭐⭐⭐
Richard E. Miller
Satisfied Customer
"Converts files in seconds! Finally a tool that's both fast and simple to use."
⭐⭐⭐⭐⭐
Wei Chen
Happy User
"I'd been searching for reliable conversion software forever — reaConverter has everything I need! After installing and watching the tutorial, I had my files converted to the perfect format in minutes. Flawless experience!"
⭐⭐⭐⭐⭐
Sanjay Mehta
Satisfied Customer

GRB to CAL Conversion: FAQ

What are GRB files?

GRB is a raster image format associated with two calculator models produced by Hewlett Packard in the 1990s: the HP 48 and the HP 49. Both could be used for advanced algebraic operations and calculations and were considered innovative at the time of their release. GRB images most likely contain screen caps or other type of data connected to these devices. They are rare and difficult to open with regular image viewers.

What are CAL files?

A CAL image file represents a monochrome bitmap image that uses the CALS raster image standard for storing graphics data. This standard was created in the 1980s by the US Department of Defence as a compressed interchangeable image format. CAL and CALS are extensions used for similar purposes.

Can reaConverter convert GRB to CAL?

Yes! reaConverter instantly converts .grb to .cal with perfect quality preservation. With its batch processing feature, you can convert multiple files at once in just a few clicks. You can even convert images directly from Windows Explorer using the right-click menu — fast and convenient.

Can I convert GRB to CAL online?

If you only need to convert a few GRB files to CAL format, feel free to try our free online free online GRB to CAL converter — perfect for small batches with no installation needed!

How can I turn GRB files into CAL on my computer?

The best way to change GRBs to CALs on your PC is to install a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from GRB to CAL.

How can I automate GRB to CAL files conversion?

reaConverter supports all the most useful automation features such as right-click сonversion and Watch Folders for the most efficient automated files conversion in any software of this type.

Is there a way to convert GRB files to CAL using the command prompt?

reaConverter provides full access to all its features via Windows command line, including a high-performance command-line grb to cal converter for batch processing.

What else can I do with reaConverter?

Change format settingsChange DPIConvert Gerber filesCrop imageConvert PDF files

Find out more

Get advanced software for file conversion, processing, and editing, giving you complete, precise control over your work.
Download
reaConverter
Buy Now
reaConverter software