The JWST Exposure Time Calculator (ETC) is a pixel-based ETC paired with a modern graphical user interface. It supports all JWST observing modes: imaging, spectroscopy (slitted, slitless, and IFU), coronagraphy, and aperture masking interferometry.


The JWST Exposure Time Calculator (ETC) has advanced features that go well beyond those in previous exposure time calculators; this includes algorithms that accurately model data acquisition and post-processing, as well as functionality for users to efficiently explore parameter space. The graphical user interface provides enhanced capabilities supporting multiple workflows. For example, users can create workbooks to manage related sets of calculations, can create complex astronomical scenes with multiple sources, and can compare the results of multiple calculations. 

More about JWST ETC

JWST Exposure Time Calculator Overview

JWST ETC Calculations Page Overview

JWST ETC Scenes and Sources Page Overview

JWST ETC Images and Plots

JWST ETC Reports

JWST ETC Downloads

JWST Backgrounds

JWST ETC Point Spread Functions

JWST ETC Instrument Throughputs

JWST ETC Source Spectral Energy Distributions

JWST ETC Target Acquisition

JWST ETC to APT Interface Support Information

JWST APT-ETC Connectivity

How to use JWST ETC

JWST ETC New User Guide

JWST ETC Creating a New Calculation


JWST ETC Defining a New Scene

JWST ETC Defining a New Source

JWST ETC Defining an Extended Source

JWST ETC Batch Expansions

JWST ETC Using the Sample Workbooks

JWST ETC Sharing Workbooks

JWST ETC User Supplied Spectra

JWST ETC Strategies

JWST ETC Wavelength of Interest/Slice

JWST ETC Backgrounds 

Video Tutorials

How to use JWST ETC Python Code Interface

JWST ETC Pandeia Engine Tutorial

External JWST ETC links and documents

Go to the on-line JWST Exposure Time Calculator Tool

Last updated

Updated November 5, 2018

  • Updated for ETC v1.3.

Published May 03, 2017

The format for 'Last updated' is shown below. Enter updates above this internal"Comment" box. Only enter major updates (not typos or formatting changes).

Updated April 5, 2017

  • Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam fermentum vestibulum est. Cras rhoncus. 
  • Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Sed quis tortor. 

Published March 2, 2017