Blackbody Radiation Calculator
Calculate blackbody radiant power, peak wavelength, and spectral exitance using Stefan-Boltzmann and Wien displacement laws.
Blackbody Radiation Laws
An ideal blackbody emits electromagnetic radiation according to its absolute temperature. The Stefan-Boltzmann law gives total radiant exitance; Wien's displacement law gives the wavelength at peak spectral emission.
Stefan-Boltzmann Law
$$j^* = \sigma T^4$$With \(\sigma = 5.67 \times 10^{-8}\,\text{W/m}^2\text{K}^4\) and \(T\) in kelvin.
Wien Displacement Law
$$\lambda_{\max} = \frac{b}{T}$$With Wien constant \(b = 2.898 \times 10^{-3}\,\text{m·K}\).
Frequently Asked Questions
Can I enter Celsius?
Yes. Select Celsius and the calculator converts to kelvin before applying both radiation laws.
What is radiant exitance?
Radiant exitance \(j^*\) is total power radiated per unit surface area from a blackbody, in W/m².
Why does peak wavelength shift with temperature?
Hotter objects radiate more at shorter wavelengths. The Sun near 5800 K peaks in visible light; a room-temperature object peaks in the infrared.
Do real surfaces match a blackbody?
Real emitters are gray bodies with emissivity less than 1. Multiply \(j^*\) by emissivity for a practical estimate.
Related Tools
Monod Kinetics Calculator
Blood Pregnancy Test Calculator
Password Entropy Calculator
Grade Calculator
MIPI Calculator
Binary Bitwise AND
Date Pattern Generator
Calories Burned Biking Calculator
Show HSL Image Colors
Relative Standard Deviation Calculator
Bond Price Calculator
Count Unicode Characters
AC Wattage Calculator
Separate Integer Digits
0-60 Quarter Mile Calculator
Benzodiazepine Conversion Calculator
Taco Bar Calculator
Check If Image Is PNG
Punycode Converter
Law of Cosines Calculator