Math & Science
Wavelength Frequency Calculator
Convert between wavelength, frequency, and energy
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What is the EM spectrum?
Radio < Microwave < IR < Visible < UV < X-ray < Gamma, in order of increasing frequency/energy.
What is visible light range?
Approximately 380-700 nm wavelength, or 430-770 THz frequency.
Why use eV for energy?
Electronvolt is convenient for photon energies. 1 eV = 1.6×10⁻¹⁹ J.
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About this tool
This Wavelength Frequency Calculator turns your inputs into practical results. Provide Value, Input, and Unit to calculate Wavelength and Frequency.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.