Effective vs. Efficient: What’s the Difference?

There are many words in the English language that have very similar meanings but different applications.

The two words effective vs. efficient fall into this category. They both generally mean “having an effect,” but each word has its own distinctive application.

What is the Difference Between Effective and Efficient?

Today, I want to discuss the differences between these two words and how to use them in a sentence. I will go over their definitions, their functions and, at the end, I will give a few tricks to keep track of them.

After reading this post, you should never mix up effective or efficient again.

When to Use Effective

commonly misspelled words phrasesEffective functions as an adjective and is defined as having an intended or desired effect.

  • The young politician was a very effective public speaker.
  • I need to develop some more effective study habits; I failed my last test.
  • We need an effective solution for everyone.

The word effective focuses on whether or not something is accomplished. It doesn’t focus on how something is done, but rather, if it is done at all.

Efficient, on the other hand, focuses on how something is done. Was it done with little waste or expense? (See below.)

When to Use Efficient

effective versus efficient grammarEfficient also functions as an adjective and is most commonly defined as acting or producing effectively with minimum waste, expense, or unnecessary effort.

  • My new car is very fuel-efficient, and it gets 40 miles per gallon.
  • I just had new energy-efficient windows put in the house.
  • We are losing too much revenue; we need a more efficient means of production.

This definition of efficient has strong economic connotations, but there is one additional definition of the word that bears no economic meaning.

In addition to its economic meanings, efficient can further be defined as acting directly to produce an effect.

In this sense, something that is efficient is something that causes change to start or stop. This is usually the thing (or person) that brings something about.

For example, in the case of a statue or painting, it is a person chiseling the rock and stroking the brush that causes the transformation. In this example, the artist would be said to be the efficient cause.

This use of efficient is less common in everyday usage, but it quite common to see in philosophical and scientific journals.

Efficient vs. Effective: Let’s Compare Examples

cost effective vs cost efficientIf you’re still not entirely clear when to use which word, efficient or effective, don’t worry. Here’s a real life example comparing the two words that should make their uses perfectly clear.

Think about these two words when describing a public speaker, as we did in our first example.

  • The young politician was a very effective public speaker.

If you were to call someone an effective speaker, you might think of someone who is convincing or persuasive, someone whom people understand, someone who is relatable, etc.

Conversely, if you were to call someone an efficient speaker, you might think of someone who says what needs to be said and nothing more. He or she gets to the point and doesn’t waste time with small talk or pleasantries.

As you can see, these words clearly evoke a very different kind of speaker, so it’s important not to mix them up.

Tricks to Remember the Difference

Think of the word efficiency as a science: the science of minimizing waste, time or effort. Science and Efficiency have similar internal spellings, both containing “CIENC.”

Think of something as being effective as whether or not it got the job done. It may not have been pretty (or efficient), but it got it done. Both effective and done end in the letter “E.”


Both efficient and effective have similar meanings, but they have their own distinct applications. Here’s how to never mix up efficient or effective again.

Effective means having a desired effect. Was something accomplished at all?

Efficient means accomplishing something with little waste. Was it accomplished efficiently?