Effective vs. efficient?

What is the difference between effective and efficient?

When something produces an effect, we can say it’s effective or efficient. But while these buzzwords have similar meanings and spellings, that doesn’t mean we should use them the same (especially if you’re confusing the terms with the homophone affective).

Generally speaking, the word effective describes anything that can produce an intended result. If you complete your daily tasks for the day, good job! You are effective. 

But what if your daily tasks involved sending out, oh, I don’t know… a few hundred emails? (Sounds like a big waste of time, if you ask me.) Let’s say you managed to automate your daily emails through a software service: you could theoretically save an entire day’s worth of work and complete your daily tasks with less time and effort. 

If that’s the case, you’re not just effective –– you’re efficient. And that’s essentially the difference between these tricky adjectives. 

We can use both effective and efficient to mean “capable of producing an expected result.” The difference is that “efficient” describes production that is faster, easier, and requires fewer resources.

What does effective mean?

The adjective effective describes people or inanimate objects (e.g., a machine, technique, or system) as “capable or successful in producing an intended or desired result.” Similar words include the adverb effectively (“in an efficient manner”) and the noun effectiveness (“the degree to which something produces a desired result”). 

Sentence examples: 

• “Day planners are an effective way to structure time management.” 
•  “Accountability partners are an effective solution for chronic procrastination.” 
• “Effective leaders understand the true value of the big picture.”
• “Project management software is an effective way to improve team leads, recruitment strategies, sales processes, and performance reviews.”
• “It’s better to do the right things effectively than complete the wrong things efficiently.”
• “The effectiveness of team leaders depends on strong organization skills, interpersonal cohesion, and the proper delegation of tasks.”

We also use effective to describe inanimate systems when referencing a policy or law. In this case, the adjective specifically means “in effect” or “operative.” Synonyms include in effect, in force, official, operative, signed and sealed, and valid. 

Sentence examples: 

• “The CEO’s resignation was effective almost immediately.”
• “The governor’s stay-at-home orders are effective as of May 5, 2021.”
• “Effective January 1, 2022, all student applicants are required to submit current GRE scores to apply for The School of Liberal Arts.” 

Similarly to law or policy, effective can also describe something as “actual” or “existing in fact.” At times, this sense of effective corresponds to the adverb effectively when it means “actually but not explicitly” or “essentially, basically.” Synonyms of this sense include concrete, concluding, closing, existent, factual, final, genuine, real, true, ultimate, and very. 

Sentence examples:

• “All imported goods are taxed at the effective rate of 4.5 percent.”
• “The million-dollar home is selling for the effective price of $809,000.”

Synonyms

Constructive, effectual, efficacious, efficient, fruitful, functional, operative, potent, powerful, productive, successful. 

Antonyms

Fruitless, ineffective, ineffectual, inefficient, inoperative, shaky, unfruitful, unproductive, useless, unsound.

What does efficient mean?

When describing a system or machine, the adjective efficient means “capable of producing desired results in the best possible manner” (i.e., requires limited resources).

Similar terms include the adverb efficiently (“in an efficient manner“) and the noun efficiency (“the degree to which maximum productivity is achieved with the least amount of resources“). 

Sentence examples:

• “The new study’s methodology is more efficient because it requires fewer steps.”
• “Providing customer service through chat is more efficient because participants can answer messages with their phones in any environment.” 
• “Efficient leaders can organize important tasks with less time and effort.” 
• “Automation is the most efficient way to eliminate unnecessary tasks and focus on the right goals.”
• “If we can manage the budget more efficiently, annual profit margins will inevitably increase.”
• “Efficiency is key when you’re dealing with a limited amount of resources.”

When describing a person, however, efficient means “involving the immediate or direct agent in producing a result” or “working in an optimized and well-organized manner.”

Sentence examples: 

• “Jordan is an efficient employee because he can complete nine hours of work in six.” 
• “An efficient sales team member understands that the best use of their time is achieving customer satisfaction.” 

Lastly, we can use the adjective efficient in combination with something it describes so long as the object utilizes the least amount of resources, energy, and time. 

Sentence examples:

• “Wind turbines are an energy-efficient alternative to burning coal.” 
• “ZoomCare provides cost-efficient health care to low-income patients.”
• “Compositing is not only environmentally sustainable but a cost-efficient way to produce high-quality crops.”

Synonyms

Effective, effectual, efficacious, fruitful, operative, logical, methodical, orderly, potent, productive, streamlined, structured, systematic, systematized, well planned.

Antonyms

Fruitless, ineffective, ineffectual, inefficient, inoperative, unfruitful, unproductive, useless.

How to use effective, efficient, efficacious, and effectual in a sentence?

As noted by Garner’s Modern English Usage, the adjectives effective, efficacious, efficient, and effectual all describe something as “having an effect,” but they require different contexts (Garner 320–321).

When to use effective?

The adjective effective either describes a task or the operator as having “a high degree of effect.” What this means is that the doer or task is highly capable of producing a desired outcome. The only other time it’s appropriate to use effective is when we’re describing a law, policy, or rule as “coming into effect” (320).

Sentence examples:

• “The smarter, more effective leaders will harness behavior analytics to build healthier, more sustainable teams that deliver better results.” — Forbes
• “U.S. to restrict travel from India effective May 4 as Covid surge devastates the country.” — CNBC

When to use efficient?

While this adjective is increasingly more relevant for economics, the best way to use efficient is to describe a competency for performing a task or, when describing a tool or action, “capable of bringing about a desired effect” with the least amount of resources, effort, or time. 

In other words, this adjective best describes something with a potential for success rather than something that has already generated the ultimate goal in mind (so long as it’s optimized). 

Sentence example:

• “That’s because ETFs are generally more tax-efficient, spinning off fewer capital-gain disbursements that for some could soon become a lot more costly.” — Bloomberg

When to use efficacious?

The adjective efficacious describes a task or object that is “certain to have the desired effect” due to a unique quality or virtue (320). 

Sentence example:

• “Mayo Clinic Vaccine Research Group Director Dr. Gregory Poland said all vaccines are highly efficacious against death and hospitalization.” — Bloomberg

When to use effectual?

The adjective effectual describes the accomplishment of an intended outcome as “achieving the complete effect aimed at” (321). However, the implicit nature of this adjective is that it describes an inanimate topic, so make sure to avoid using it to describe a person.

Sentence example:

• “It was aimed at “preventing tumults and riotous assemblies,” and made provisions for ‘more speedy and effectual punishing’ of those who engaged in civil unrest.” — Slate

Usage note: Writers who use the negative “ineffectual” to describe people are always surprised to learn they’ve been using it wrong the whole time, but this is why GMEU calls this adjective the “rarest” and “most troublesome” derivative of effect (321). 

Summary

• Effective best describes the actual power or capability to produce an effect.
• Efficient describes a potential for results produced with less time, resources, and energy. 
• Efficacious implies something is effective due to a special quality or power.
• Effectual describes the results of an outcome after the fact. 

Additional reading

Interested in more lessons like effective vs. efficient? Check out The Word Counter’s weekly content on topics such as: 

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• Lessor vs. lessee?
• Skillset vs. skill set?
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FAQ: Related to effective vs. efficient

What does efficacy mean?

According to Lexico (i.e., the Oxford Dictionary), the term efficacy means “the ability to produce a desired or intended result.” The noun is directly related to the adjective efficacious (listed above). 

What is the Pareto principle?

Also known as the “80-20 rule,” the Pareto principle teaches business managers to believe that “80 percent of consequences stem from 20 percent of causes.” Under this theory, we can hypothesize outcomes, such as:

• Twenty percent of the most dangerous sports account for 80 percent of all sports injuries.
• Eighty percent of your day is affected by twenty percent of your decisions.

Test Yourself!

Test how well you understand the difference between effective and efficient with the following multiple-choice questions. 

1. True or false?: The words effective and efficient have different spellings but mean the same thing.
   a. True
   b. False
2. The adjective efficient means _________________.
   a. Capable of producing an intended result
   b. Operative or in effect
   c. Capable of producing desired results in the best possible manner
   d. Actual or existing in fact
3. Choose the best antonym of the adverb efficiency.
   a. Ineffective
   b. Inefficiently
   c. Inefficient
   d. Inefficiency
4. Measurable metrics involving the use of resources are not necessarily important for which term(s)? 
   a. Effective
   b. Efficient
   c. Efficiency
   d. B and C
5. The word effectiveness means _________________.
   a. Capable of producing desired results in the best possible manner
   b. The degree to which maximum productivity is achieved with the least amount of resources
   c. The degree to which something produces a desired result
   d. capable or successful in producing an intended or desired result

Answers

1. B
2. C
3. D
4. A
5. C

Sources

1. “All Covid-19 Vaccines are Efficacious: Mayo Clinic.” Bloomberg, bloomberg.com, 26 Apr 2021.
2. Ballentine, C., Greifeld, K. “Rich Americans Fleeing Tax Hikes May Turbocharge Shift to ETFs.” Bloomberg, bloomberg.com, 2 May 2021.
3. Bunkley, N. “Joseph Juran, 103, Pioneer in Quality Control, Dies.” The New York Times, nytimes.com, 3 Mar 2008.
4. “Effective.” The American Heritage Dictionary of the English Language, 5th ed., Houghton Mifflin Harcourt Publishing Company, 2021. 
5. “Effective.” Lexico, Oxford University Press, 2021.
6. “Effective.” The Merriam-Webster.com Thesaurus, Merriam-Webster Inc., 2021.
7. “Efficient.” The American Heritage Dictionary of the English Language, 5th ed., Houghton Mifflin Harcourt Publishing Company, 2021. 
8. Efficient.” Lexico, Oxford University Press, 2021.
9. “Efficient.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., 2021.
10. Garner, B. “Effective; efficacious; efficient; effectual.” Garner’s Modern American Usage, 3rd ed., Oxford University Press, 2009, p. 320–321. 
11. Kohen, I. “Building Healthier, More Sustainable Teams With Behavior Analytics.” Forbes, forbes.com, 19 Apr 2021.
12. Morton, E. “What It Actually Means to ‘Read the Riot Act’ to Someone.” Slate, slate.com, 4 Sept 2015.