Calculators
De Broglie Wavelength Calculator
Calculate de Broglie wavelength in meters, nanometers, and angstroms from momentum magnitude in kg·m/s, privately in your browser.
Find matter-wave wavelength from momentum.
The de Broglie relation is λ = h/p, where h = 6.62607015 × 10⁻³⁴ J·s is the exact Planck constant and p is momentum magnitude in kg·m/s. Results are given in meters, nanometers (1 nm = 10⁻⁹ m), and angstroms (1 Å = 10⁻¹⁰ m). For p = 1e-24 kg·m/s, λ = 6.62607015e-10 m = 0.662607015 nm = 6.62607015 Å. Doubling momentum halves wavelength. For a massive particle at speeds much smaller than light speed, p ≈ mv; at relativistic speeds use relativistic momentum instead. This tool accepts momentum directly and makes no nonrelativistic approximation. Enter a positive magnitude: direction does not change wavelength, and zero momentum has no finite wavelength under this formula. Supported momentum magnitudes range from 1e-50 to 1e50 kg·m/s. Results use browser floating-point arithmetic rounded to 12 significant digits. This computes a matter-wave wavelength, not a particle trajectory or wave amplitude. Inputs stay on your device.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What is the de Broglie wavelength formula?
λ = h/p, with Planck constant h = 6.62607015 × 10⁻³⁴ J·s and momentum magnitude p in kg·m/s. The resulting wavelength is in meters.
What is the wavelength for momentum 1e-24 kg·m/s?
It is 6.62607015e-10 m, or 0.662607015 nm and 6.62607015 Å.
Can I use mass times velocity for momentum?
Use p ≈ mv only when speed is much smaller than the speed of light. For relativistic speeds use relativistic momentum. Enter the resulting momentum magnitude into this calculator.
Why must momentum be positive?
Wavelength depends on momentum magnitude, not its direction. Zero momentum produces no finite wavelength in λ = h/p. Enter magnitudes from 1e-50 to 1e50 kg·m/s.
How does momentum affect wavelength?
Wavelength is inversely proportional to momentum: doubling momentum halves wavelength.
Are my inputs uploaded?
No. Calculation and copying run in your browser. Reset restores the 1e-24 kg·m/s example.