Radiance Unit Converter
Convert radiance between W/(m²·sr), W/(cm²·sr) and CGS energy-area-time units.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Normalize power and projected area while retaining the solid-angle denominator.
Radiance in W/(m²·sr) = value × power factor / (area factor × solid-angle factor)
Worked example
1 mW/(cm²·sr) is 10 W/(m²·sr). One erg/(s·cm²·sr) is 0.001 W/(m²·sr).
Assumptions and input details
Radiance uses projected area and solid angle. Keep the same direction and radiometric spectral integration convention. It is not luminance in cd/m², irradiance or radiant intensity. No viewing geometry, spectrum, luminous efficiency or emitting-surface temperature is inferred.
References: BIPM: SI quantities and prefixes · NIST: spectral irradiance unit conventions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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