Nuclear Fusion Energy Calculator Formula

Understand the math behind the nuclear fusion energy calculator. Each variable explained with a worked example.

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Formulas Used

Mass Difference

mass_diff = mass_reactants - mass_products

Energy Released

energy_mev = (mass_reactants - mass_products) * 931.494

Energy per Nucleon

energy_per_nucleon = (mass_reactants - mass_products) * 931.494 / round(mass_reactants)

Variables

VariableDescriptionDefault
mass_reactantsTotal Mass of Reactants(u)5.0305
mass_productsTotal Mass of Products(u)5.0116

How It Works

Nuclear Fusion Energy

Fusion of light nuclei releases energy because the products have higher binding energy per nucleon. The energy comes from the mass difference, just like fission.

Formula

E = delta_m × 931.494 MeV/u

The D-T fusion reaction (²H + ³H → ⁴He + n) releases 17.6 MeV. Per unit mass, fusion fuel releases about 4 times more energy than fission fuel, making it the ultimate energy source.

Worked Example

D-T fusion: D(2.0141) + T(3.0164) → He-4(4.0026) + n(1.0087) + energy.

mass_reactants = 5.0305mass_products = 5.0116
  1. 01Reactant mass = 2.0141 + 3.0164 = 5.0305 u
  2. 02Product mass = 4.0026 + 1.0087 = 5.0113 u
  3. 03delta_m = 5.0305 - 5.0116 = 0.0189 u
  4. 04E = 0.0189 × 931.494 = 17.6 MeV

Ready to run the numbers?

Open Nuclear Fusion Energy Calculator