marginal utility

« Back to Glossary Index

Marginal utility is the extra satisfaction or benefit a person receives from consuming one additional unit of a product or service, while keeping all other factors the same.

Key points:

  • It measures the change in total satisfaction caused by consuming one more unit.
  • Usually, as you consume more of a specific item, the marginal utility decreases because each new unit provides less value than the one before it.
  • If marginal utility is positive, your total satisfaction grows. If it is zero, you have reached maximum satisfaction. If it is negative, your total satisfaction drops.

Formula:

Marginal Utility (MU) = Change in total utility / Change in quantity consumed

Relationship between Total Utility (TU) and Marginal Utility (MU):

  • If MU is greater than 0, TU is increasing.
  • If MU is 0, TU is at its highest point.
  • If MU is less than 0, TU is decreasing.

Mathematical note:

Marginal utility represents the rate of change in total utility. It reaches zero exactly when total utility is at its peak.