Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Wavelength (nm)

Emission wavelength in nanometers.

Convert a wavelength in nanometers to photon energy in electronvolts using E = 1239.84 / lambda. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Photon energy (eV)

Energy of one photon at that wavelength.

• LED forward voltage, current, power, efficacy, intensity, wavelength, and viewing angle depend on junction temperature, binning, drive waveform, optics, aging, and the manufacturer's measurement convention. Thermal design and absolute maximum ratings remain separate.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Beamwidth Approx

  Approximate the parabolic dish half-power beamwidth in degrees as 70 x lambda / D; wavelength and dish diameter must be positive.

• Effective Aperture

  Compute the antenna effective aperture in square meters as Ae = lambda^2 x G / (4 x pi); wavelength and linear gain must be positive.

• Far Field Boundary

  Compute the far-field boundary of an aperture as Rf = 2 x D^2 / lambda; aperture size and wavelength must be positive.