How to use the blackbody radiation energy density calculator
Find the energy density of thermal radiation at a given temperature, such as the cosmic microwave background. Enter temperature in the field above; the radiation energy density are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “radiation energy density”, “CMB energy density”, “blackbody energy per volume”, “calculate blackbody radiation energy density”, “find radiation energy density”.
Formula
Variables
- T — Temperature (K)
Worked example
With temperature = 2.725 K, the calculator gives radiation energy density ≈ 4.1717 × 10⁻¹⁴ J/m³; radiation energy density ≈ 4.1717 × 10⁻²⁰ J/cm³.
Frequently asked questions
What is the blackbody radiation energy density calculator used for?
Find the energy density of thermal radiation at a given temperature, such as the cosmic microwave background. It helps with questions such as “radiation energy density”, “CMB energy density”, “blackbody energy per volume”.
What is the formula for the blackbody radiation energy density calculation?
Radiation energy density (J/m³) = 4 × SIGMA / CLIGHT × T^4. Radiation energy density (J/cm³) = [Radiation energy density] × 1e-6. Here T is temperature (K).
What inputs do I need for the blackbody radiation energy density calculator?
You need temperature in K. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the blackbody radiation energy density calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the blackbody radiation energy density result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.