de Broglie Wavelength Calculator

Calculate de Broglie wavelength, momentum, velocity, or mass using λ = h/p. Features momentum units (kg·m/s, g·cm/s, eV/c), velocity units (m/s, km/s, cm/s, mph), mass units (kg, g, amu, eV/c²), and wavelength units (m, nm, pm, Å, fm). Includes common particles (electron, proton, neutron, etc.) and relativistic mode toggle. Perfect for quantum physics students.