De Broglie Wavelength Calculator

Calculate the de Broglie wavelength of a particle from its mass and velocity or kinetic energy.

Input Parameters

Result

Enter values and click Calculate

Common Particle Masses

Particle Mass (kg) Symbol
Electron 9.109 × 10⁻³¹ e⁻
Proton 1.673 × 10⁻²⁷ p⁺
Neutron 1.675 × 10⁻²⁷ n

Planck's constant h = 6.626 × 10⁻³⁴ J·s

Copied!

Summary

Calculate the de Broglie wavelength of a particle from its mass and velocity or kinetic energy.

How it works

  1. Select a calculation mode: velocity + mass or kinetic energy + mass.
  2. Choose a preset particle (electron, proton, neutron) or enter a custom mass in kilograms.
  3. Enter the velocity in meters per second or kinetic energy in electron-volts.
  4. The calculator applies lambda = h/p, where p = mv for velocity mode and p = sqrt(2mKE) for energy mode.
  5. Results appear instantly in both picometers (pm) and nanometers (nm).

Use cases

  • Verify homework or exam solutions for quantum mechanics courses.
  • Compare the wavelength of electrons versus heavier particles at the same speed.
  • Explore how kinetic energy affects the wave nature of sub-atomic particles.
  • Understand why macroscopic objects have negligibly small de Broglie wavelengths.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu