To solve the equation \( 10^{\log x} = 10^{18} \), we can use the property that if the bases are the same, we can set the exponents equal to each other. Thus, we have:
\[ \log x = 18 \]
Next, we can exponentiate both sides to solve for \( x \):
\[ x = 10^{18} \]
So, the value of \( x \) is \( 10^{18} \).
The answer is 10^18.