Convert CAL to FITS

CAL to FITS conversion that keeps your files private. reaConverter runs offline on your computer with full batch processing support.

reaConverter transforms CAL files to FITS quickly and reliably. Drag in folders, set your options, click Convert, done. No cloud accounts, no file uploads, no complicated setup. Just install and start converting.

1. Download and Install reaConverter

reaConverter is a standalone Windows app — download, install, and start converting CAL files in under two minutes. Need edits? Resize, rotate, or add watermarks during conversion.

Install reaConverter

2. Load your CAL files

Add your CAL files to reaConverter. Whether it's a handful or an entire archive, the batch engine processes them efficiently.

Browse for files, drag them in, or add entire folders at once. reaConverter queues everything automatically.

3. Select FITS as output format

Pick FITS as the output format. Set the destination folder and optionally configure resolution, quality, or file naming.

4. Start CAL to FITS conversion

Start the conversion with one click. reaConverter handles everything and notifies you when it's done.

When the batch finishes, your FITS files are ready in the destination folder you chose earlier.

CAL to FITS Converter

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

Download Free Trial

Do more with your images

Converting CAL images for use in a larger project? With reaConverter, you can convert, edit, and enhance your images in one streamlined process.

Our range of editing options includes such image processing actions as Resize, Rotate, Crop, Color Replace, Watermarks and more. Adjust actions include RGB, HLS, HSV, Brightness and Contrast. Auto-processing options are also available, such as auto-rotate and auto-crop.

Image editing tools

User Reviews

Average User Rating:
Last updated on January 25, 2026

"reaConverter makes FITS conversion incredibly easy. We batch convert astronomical images to standard formats for presentations and analysis, all automated through the command-line. It’s fast, reliable, and handles large datasets without issues."

Laura N.

Astrophysics Research Assistant

"Essential for our astroimaging pipeline! reaConverter perfectly handles FITS files from our research telescope, preserving all WCS coordinates and photometric data during batch conversion to TIFF. Now we process 100+ deep-sky exposures nightly without losing critical metadata for our exoplanet studies!"

Joseph Wilson

Satisfied Customer

"Finally an app that actually opens my weird files! Saves me from format frustration daily."

Kyle Brooks

Happy User

"This converter delivers exceptionally quick format conversions with reliable results every time."

Brian White

Happy User

"Security was our top concern when evaluating file conversion tools. reaConverter’s offline mode and role-based access controls let us lock it down for sensitive environments. No unexpected network calls or bloat — just clean, fast conversions. Even passed our pen-testing scans without a hitch."

Marcus White

Healthcare IT

"The step-by-step video makes conversion foolproof. I'd recommend this to my grandma - it's that well-explained!"

DeShawn M. Thompson

Happy User

CAL to FITS Conversion: FAQ

Can reaConverter convert CAL to FITS?

Yes! reaConverter instantly converts .cal to .fits 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.

What is reaConverter used for?

reaConverter is a software program used for converting images and other types of files from one format to another. It supports a wide range of file formats and allows users to convert multiple files at once, making it a valuable tool for graphic designers, photographers, and other professionals who work with digital images. reaConverter also includes features for resizing, cropping, and editing images, along with batch processing capabilities that help automate repetitive tasks.

Can I convert CAL to FITS online?

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

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

The best way to change CALs to FITSs 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 CAL to FITS.

How can I automate CAL to FITS 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 CAL files to FITS using the command prompt?

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

What else can I do with reaConverter?

Convert vector images Convert picture color space Convert CAD formats Set image bit depth Convert PDF