The spark plug gap for a 1994 Buick Century depends on the engine. You'll need to check your owner's manual for the precise specification. However, a common range for Buick Centuries of that year is
0.040 to 0.050 inches (1.02 to 1.27 mm).
Crucially: Don't rely solely on online information. Always consult your owner's manual for the correct specification for your specific engine. Using the wrong gap can lead to poor engine performance and damage.