Convert FITS to CAL

Tired of slow online converters? reaConverter transforms FITS to CAL instantly — right on your desktop, no upload needed.

Batch FITS to CAL conversion doesn't have to be complicated. reaConverter processes entire folders with consistent quality settings. Works offline with no internet required — convert anywhere, anytime.

1. Download and Install reaConverter

reaConverter installs quickly on any Windows PC. No dependencies, no bloatware — just a clean setup that's ready to use immediately. Apply image edits like resize, crop, or color adjustment while converting.

Install reaConverter

2. Load your FITS files

Open reaConverter and import your .fits files. No file limits, no slowdowns. Add as many as you need.

Drag files into the window, use the Add Files button, or select entire folders.

3. Select CAL as output format

Select CAL as target format and pick where to save results. You can keep default settings or fine-tune the output.

4. Start FITS to CAL conversion

Hit Convert to process your files. The log window shows progress, timing, and status for every file.

Conversion complete? Your CAL files are saved to the destination folder, ready to use.

FITS to CAL Converter

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

Download Free Trial

Do more with your images

Converting FITS 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 18, 2026

"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

"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

"An ultra-fast solution for minimizing file sizes. The entire conversion process takes just 3 minutes!"

Logan B.

Satisfied Customer

"I use the online converter — it’s quick and hassle-free!"

Jian Wong

Happy Online User

"Working in a print studio means constantly juggling obscure file formats. I used to waste hours Googling converters or installing random software — until reaConverter became my Swiss Army knife. Install it once, and you're set forever. No internet? No problem!"

Helen Evans

Satisfied Customer

"An excellent program! I use it regularly in my work - it supports nearly every file format imaginable. The interface is intuitive and runs flawlessly every time."

Roger Cook

Happy User

FITS to CAL Conversion: FAQ

Can reaConverter convert FITS to CAL?

Yes! reaConverter instantly converts .fits 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.

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 FITS to CAL online?

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

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

The best way to change FITSs 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 FITS to CAL.

How can I automate FITS 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 FITS 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 fits to cal converter for batch processing.

What else can I do with reaConverter?

Convert DICOM files Resize picture Change file creation date Copy metadata (EXIF, IPTC)Convert RAW files