NASA logo USGS banner
Radiance Calculator
The following radiance calculator was designed for both educational and research purposes - for anyone interested in a web-based tool for quickly calculating the Planck radiance curves for various temperature bodies. Start by clicking "calculate" and then interactively experiment by plotting Planck functions for different temperatures and emissivities. You may choose different calculation parameters, plot parameters, and over-plot up to three temperature curves. You may also view the raw data or output them to a CSV file. For viewing radiance plots of thermally mixed bodies, try the Thermal Mixture Radiance Calculator. Have Fun!


Low wavelength:  µm
High wavelength:  µm
Plot 1:  
Temperature:  K
Emissivity:  (optional)
Plot 2:  
Temperature:  K (optional)
Emissivity:  (optional)
Plot 3:  
Temperature:  K (optional)
Emissivity:  (optional)
Plot Parameters (optional):  
x-axis (wavelength) increment:
x-axis (wavelength) range: to
y-axis (radiance) range: to
Auto-scale y-axis:
x-axis Scale: Log Linear
y-axis Scale: Log Linear




Spec. Rad.
  Wavelength (µm)  

Constants (from NIST):

Speed of Light (c)2.99792458e+8m*s-1
Planck constant (h)6.626068963e-34J*s
Boltzmann constant (k)1.3806504e-23J*K-1
Wien constant (b)2.8977685e-3m*K
Stefan-Boltzmann constant (σ)5.670400e-8W*m-2*K-4
First Radiation constant for spectral radiance (c1) (2hc2) 1.191042759e-16W*m2*sr-1
Second Radiation constant (c2) (hc/k) 1.4387752e-2m*K

This tool was developed as part of the Education & Public Outreach program of the NASA ROSES 2009 New Investigator Program in Earth Science (NNH09ZDA001N-NIP). It is a work in progress. Please send any questions, comments, or suggestions to the PI: R. Greg Vaughan (

U.S. Department of the Interior | U.S. Geological Survey
Home | Search | Disclaimers & Privacy
Send comments to
USA.Gov: The U.S. Government's Official Web Portal