# Why is ""^13 "C NMR" less sensitive?

There are two main reasons why $\text{^13"C}$ NMR is less sensitive than $\text{^1"H}$ NMR.
• A $\text{^13"C}$ nucleus has about $\text{1/400}$ the sensitivity of a $\text{^1"H}$ nucleus to the NMR phenomenon.
• Only about 1.1 % of all carbon atoms are $\text{^13"C}$.