Wavelength-Energy Calculator
Convert between wavelength and photon energy using E = hc/λ across the EM spectrum.
What Is Wavelength-Energy Calculator?
This calculator implements Convert between wavelength and photon energy using E = hc/λ across the EM spectrum. — a core relationship in physics.
The formula follows from fundamental principles and applies across a wide range of physical scenarios.
Pay attention to units and sign conventions when using these calculations in practice.
Results are valid within the stated assumptions; real systems may deviate at extremes.
Formula Reference Table
| Solve For | Formula | Notes |
|---|---|---|
| Photon energy | E = hf = hc/λ | h = 6.626×10⁻³⁴ J·s |
| eV shortcut | E(eV) = 1240/λ(nm) | Very convenient for visible light |
| Wavelength from E | λ = hc/E | m |
| Visible range | 400–700 nm = 1.77–3.1 eV | Blue to red |
| X-ray range | 0.01–10 nm = 0.1–100 keV | |
| Gamma rays | > 0.01 nm = > 100 keV | Nuclear transitions |
3 Worked Examples
λ = 532 nm.
- E = 1240/532 = 2.33 eV = 3.73×10⁻¹⁹ J
E = 10 keV = 10,000 eV.
- λ = 1240/10000 nm = 0.124 nm = 1.24 Å
2.4 GHz: f = 2.4×10⁹ Hz, v=c.
- λ = c/f = 3×10⁸/2.4×10⁹ = 0.125 m = 12.5 cm
- E = hf = 6.626×10⁻³⁴ × 2.4×10⁹ = 1.59×10⁻²⁴ J = 9.93×10⁻⁶ eV
Real-World Applications
Common Mistakes to Avoid
SI units.
Correct variant.
Ideal conditions.
Check conventions.
Check squaring.
Frequently Asked Questions
Related Physics Calculators
Formula Explorer connections
Interpretation: This relationship connects motion, force, momentum, work or energy in a mechanical system. Assumption: Choose a consistent reference direction and unit system. The model may assume constant acceleration, rigid bodies, negligible losses or an isolated system.