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Wien's Law Calculator.

Calculate peak thermal-radiation wavelength from absolute temperature.

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Absolute temperature

Peak wavelength

0.000000m

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Use Cases

Astronomy: Determine star color

Estimate the peak emission wavelength of a star from its surface temperature to infer its color and spectral class.

Example: For a star at 5800 K, the peak wavelength is about 500 nm, which appears yellow-white.

Thermal imaging and radiation studies

Find the dominant wavelength emitted by hot objects like furnaces or filaments to understand their thermal radiation characteristics.

Example: A filament at 3000 K emits peak radiation around 966 nm, in the near-infrared.

Frequently Asked Questions

What is Wien's Law?: Wien's Law states that the wavelength at which a blackbody emits the most radiation is inversely proportional to its absolute temperature. The formula is λ_max = b / T, where b is Wien's displacement constant (approximately 2.897771955e-3 m·K).
How do I use this calculator?: Simply enter the absolute temperature of the object in Kelvin (K) into the 'Absolute temperature' field. The calculator will compute the peak wavelength in meters (m) using Wien's Law.
What units does the result use?: The result is given in meters (m), which is the standard SI unit for wavelength. You can convert to nanometers (nm) by multiplying by 1e9, or to micrometers (μm) by multiplying by 1e6.

Tips & Common Mistakes

Tips

Ensure the temperature is in Kelvin (K). If you have Celsius, add 273.15 to convert.
The result is the peak wavelength in a vacuum; in other media, the wavelength may differ slightly.
For quick reference, remember that room temperature (about 300 K) gives a peak around 9.66 μm, in the infrared.
Use the result to estimate the color of a star: shorter wavelengths (blue) indicate hotter temperatures, longer (red) cooler.

Common Mistakes to Avoid

Forgetting to convert Celsius to Kelvin before entering the temperature.
Misinterpreting the result: the peak wavelength is the wavelength of maximum emission, not the total radiation.
Assuming the calculator works for non-blackbody objects; it is based on ideal blackbody radiation.

Last updated: August 13, 2026

Use Cases

Astronomy: Determine star color

Estimate the peak emission wavelength of a star from its surface temperature to infer its color and spectral class.

Example: For a star at 5800 K, the peak wavelength is about 500 nm, which appears yellow-white.

Thermal imaging and radiation studies

Find the dominant wavelength emitted by hot objects like furnaces or filaments to understand their thermal radiation characteristics.

Example: A filament at 3000 K emits peak radiation around 966 nm, in the near-infrared.

Frequently Asked Questions

What is Wien's Law?

Wien's Law states that the wavelength at which a blackbody emits the most radiation is inversely proportional to its absolute temperature. The formula is λ_max = b / T, where b is Wien's displacement constant (approximately 2.897771955e-3 m·K).

How do I use this calculator?

Simply enter the absolute temperature of the object in Kelvin (K) into the 'Absolute temperature' field. The calculator will compute the peak wavelength in meters (m) using Wien's Law.

What units does the result use?

The result is given in meters (m), which is the standard SI unit for wavelength. You can convert to nanometers (nm) by multiplying by 1e9, or to micrometers (μm) by multiplying by 1e6.

Tips & Common Mistakes

Tips

Ensure the temperature is in Kelvin (K). If you have Celsius, add 273.15 to convert.
The result is the peak wavelength in a vacuum; in other media, the wavelength may differ slightly.
For quick reference, remember that room temperature (about 300 K) gives a peak around 9.66 μm, in the infrared.
Use the result to estimate the color of a star: shorter wavelengths (blue) indicate hotter temperatures, longer (red) cooler.

Common Mistakes to Avoid

Forgetting to convert Celsius to Kelvin before entering the temperature.
Misinterpreting the result: the peak wavelength is the wavelength of maximum emission, not the total radiation.
Assuming the calculator works for non-blackbody objects; it is based on ideal blackbody radiation.

Use Cases

Astronomy: Determine star color

Estimate the peak emission wavelength of a star from its surface temperature to infer its color and spectral class.

Example: For a star at 5800 K, the peak wavelength is about 500 nm, which appears yellow-white.

Thermal imaging and radiation studies

Find the dominant wavelength emitted by hot objects like furnaces or filaments to understand their thermal radiation characteristics.

Example: A filament at 3000 K emits peak radiation around 966 nm, in the near-infrared.

Frequently Asked Questions

What is Wien's Law?

How do I use this calculator?

Simply enter the absolute temperature of the object in Kelvin (K) into the 'Absolute temperature' field. The calculator will compute the peak wavelength in meters (m) using Wien's Law.

What units does the result use?

The result is given in meters (m), which is the standard SI unit for wavelength. You can convert to nanometers (nm) by multiplying by 1e9, or to micrometers (μm) by multiplying by 1e6.

Tips & Common Mistakes

Tips

Ensure the temperature is in Kelvin (K). If you have Celsius, add 273.15 to convert.
The result is the peak wavelength in a vacuum; in other media, the wavelength may differ slightly.
For quick reference, remember that room temperature (about 300 K) gives a peak around 9.66 μm, in the infrared.
Use the result to estimate the color of a star: shorter wavelengths (blue) indicate hotter temperatures, longer (red) cooler.

Common Mistakes to Avoid

Forgetting to convert Celsius to Kelvin before entering the temperature.
Misinterpreting the result: the peak wavelength is the wavelength of maximum emission, not the total radiation.
Assuming the calculator works for non-blackbody objects; it is based on ideal blackbody radiation.