De Broglie Wavelength Calculator

Your details

Choose a preset to load its rest mass, or pick Custom mass to type your own.
Enter a velocity, a kinetic energy, or a momentum directly. The wavelength is the same physics either way.
Speed of the particle. Choose c to enter it as a fraction of the speed of light (e.g. 0.1 = 10% of c).
Turn on for speeds above ~10% of light. Uses the Lorentz factor γ so the wavelength stays accurate for fast beams.
De Broglie wavelength
7.2739e-10 mm
Wavelength in nanometres0.7274nm
Wavelength in ångströms7.2739Å
Wavelength in picometres727.39pm
Momentum (p)9.1094e-25 kg·m/skg·m/s
Speed as a fraction of c3.336e-3 c
Lorentz factor (γ)1
Kinetic energy2.8428e+0 eVeV
0.7274 nm
Sub-pm (undetectable)<0.001X-ray / fast beam0.001-0.01Atomic scale0.01-0.5Soft / large0.5+

The de Broglie wavelength is 7.274e-10 m (0.7274 nm, 727.39 pm).

  • Wavelength is inversely proportional to momentum: λ = h ÷ p, with h = 6.626×10⁻³⁴ J·s.
  • This wavelength is in the picometre range, like X-rays and electron-microscope beams.
  • Heavier or faster particles have shorter wavelengths, which is why everyday objects show no visible wave behaviour.

Next stepIf the speed is above about 10% of light, turn on the relativistic correction for a more accurate wavelength.

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