mm² to in² Converter - Square Millimeter to Square Inch

Conversion derivation

Express both mm² and in² in the same base unit m² (square meter), then cancel the shared base unit.

1. 1

   Rewrite mm² in the base unit

   $$1\mathrm{m}{\mathrm{m}}^2=0.000001{\mathrm{m}}^2$$
2. 2

   Rewrite in² in the base unit

   $$1\mathrm{i}{\mathrm{n}}^2=0.00064516{\mathrm{m}}^2$$
3. 3

   Forward conversion

   $$\begin{array}{rl}1\mathrm{m}{\mathrm{m}}^2& =\frac{0.000001\cancel{{\mathrm{m}}^2}}{0.00064516\cancel{{\mathrm{m}}^2}}\times 1\mathrm{i}{\mathrm{n}}^2\\ & =\frac{0.000001}{0.00064516}\mathrm{i}{\mathrm{n}}^2\\ & =0.0015500031\mathrm{i}{\mathrm{n}}^2\end{array}$$
4. 4

   Reverse conversion

   $$\begin{array}{rl}1\mathrm{i}{\mathrm{n}}^2& =\frac{0.00064516\cancel{{\mathrm{m}}^2}}{0.000001\cancel{{\mathrm{m}}^2}}\times 1\mathrm{m}{\mathrm{m}}^2\\ & =\frac{0.00064516}{0.000001}\mathrm{m}{\mathrm{m}}^2\\ & =645.16\mathrm{m}{\mathrm{m}}^2\end{array}$$