Ha to kcal Converter - Hartree to Kilocalorie

Conversion derivation

Express both Ha and kcal in the same base unit J (joule), then cancel the shared base unit.

1. 1

   Rewrite Ha in the base unit

   $$1\mathrm{Ha}=4.35974472\times 10^{-18}\mathrm{J}$$
2. 2

   Rewrite kcal in the base unit

   $$1\mathrm{kcal}=4,184\mathrm{J}$$
3. 3

   Forward conversion

   $$\begin{array}{rl}1\mathrm{Ha}& =\frac{4.35974472\times 10^{-18}\cancel{\mathrm{J}}}{4,184\cancel{\mathrm{J}}}\times 1\mathrm{kcal}\\ & =\frac{4.35974472\times 10^{-18}}{4,184}\mathrm{kcal}\\ & =1.042004\times 10^{-21}\mathrm{kcal}\end{array}$$
4. 4

   Reverse conversion

   $$\begin{array}{rl}1\mathrm{kcal}& =\frac{4,184\cancel{\mathrm{J}}}{4.35974472\times 10^{-18}\cancel{\mathrm{J}}}\times 1\mathrm{Ha}\\ & =\frac{4,184}{4.35974472\times 10^{-18}}\mathrm{Ha}\\ & =9.59689217\times 10^{20}\mathrm{Ha}\end{array}$$