Convert Electronvolt to British Thermal Unit (eV → BTU)

Converting electronvolts to BTU is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in electronvolts

   Start with the number of electronvolts (eV) you want to convert.
2. 2
   Multiply by 1.519 × 10^-22

   The conversion factor from eV to BTU is 1.519 × 10^-22. Multiply your value by this number.
3. 3
   Read the result in BTU

   The result is your value in BTU (BTU).

Multiply the value in electronvolts by 1.519 × 10^-22. For the reverse direction, multiply by 6.585 × 10^21.

• ✓1 eV ≈ 1.602 × 10⁻¹⁹ J.
• ✓Particle physics scales: eV → keV → MeV → GeV → TeV (1000× each).
• ✓Photon energy (eV) × wavelength (nm) ≈ 1240.

• ✗Confusing eV with V (volt) — eV is energy, V is electric potential.
• ✗Mixing scales: treating MeV as twice eV — it's a million times larger.
• ✗Using eV for macroscopic energy — unwieldy numbers.

What is the Electronvolt?

The electronvolt equals approximately 1.602176634 × 10⁻¹⁹ joules (a tiny amount of energy) and is the standard unit in atomic physics, particle physics, and semiconductor electronics. Defined as the energy gained by an electron accelerated through a potential difference of 1 volt, the eV is the natural scale for atomic and molecular energies. The energy required to ionize a hydrogen atom is 13.6 eV, the band gap of silicon (relevant for transistors and solar cells) is 1.12 eV, and visible light photons carry 1.6–3.3 eV per photon. Particle physicists routinely use MeV (million eV), GeV (billion eV), and TeV (trillion eV): the Large Hadron Collider accelerates protons to 6.5 TeV. The eV relates to the joule (1 eV ≈ 1.602 × 10⁻¹⁹ J), the kilojoule per mole (96.485 kJ/mol per eV), and atomic mass units via E = mc². It is the universal energy unit in physics literature.

• Particle physics (TeV, GeV, MeV)
• Atomic and molecular physics
• Semiconductor band gaps

What is the British Thermal Unit?

The British thermal unit (BTU) equals approximately 1,055.06 joules and is the standard unit in American HVAC, gas appliances, and air-conditioner ratings. Originally defined as the heat needed to raise 1 pound of water by 1°F, the BTU is the imperial counterpart to the calorie. American gas utilities measure delivered heat in BTUs or therms (1 therm = 100,000 BTU), and air conditioners are rated by their cooling capacity in BTU per hour (a typical window AC is 5,000–12,000 BTU/h, central AC for a medium home is 24,000–60,000 BTU/h). Furnaces are similarly rated. The BTU relates to the joule (1 BTU ≈ 1,055 J), the calorie (1 BTU ≈ 252 cal), the watt-hour (1 BTU ≈ 0.293 Wh), and the therm (100,000 BTU = 1 therm). Outside the United States, the BTU is rare; metric countries use kilojoules or kilowatt-hours for the same applications.

• US air-conditioner sizing
• US heating-system capacity
• Natural gas billing in some US regions