Ensure your units are consistent when using the ideal gas law:
\[ P \text{ (Pa)}, V \text{ (m}^3\text{)}, n \text{ (mol)}, T \text{ (Kelvin, K)}, R = 8.314\text{ J/(mol}\cdot\text{K)} \]
Alternatively, you can use:
\[ P \text{ (atm)}, V \text{ (L)}, n \text{ (mol)}, T \text{ (K)}, R = 0.0821\text{ L}\cdot\text{atm/(mol}\cdot\text{K)} \]
Temperature must always be expressed on an absolute scale (Kelvin).