extrapolation

American  

[ik-strap-uh-ley-shuhn] / ɪkˌstræp əˈleɪ ʃən /

noun

1. an act or instance of inferring an unknown from something that is known.

2. Statistics, Mathematics. the act or process of estimating the value of a variable or function outside the tabulated or observed range.

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extrapolation Cultural  

1. A mathematical procedure designed to enable one to estimate unknown values of a parameter from known values. A common method of extrapolation is to look at data on a curve, then extend the curve into regions for which there is no data. Extrapolation is often used to predict the future.

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Etymology

Origin of extrapolation

First recorded in 1870–75; extrapolat(e) + -(t)ion

Explanation

An extrapolation is kind of like an educated guess or a hypothesis. When you make an extrapolation, you take facts and observations about a present or known situation and use them to make a prediction about what might eventually happen. Extrapolation comes from the word extra, meaning “outside,” and a shortened form of the word interpolation. Interpolation might sound like a made-up word, but it’s not. An interpolation is an insertion between two points. So an extrapolation is an insertion outside any existing points. If you know something about Monday and Tuesday, you might be able to make an extrapolation about Wednesday.

Example Sentences

“When you look into the Feast of Seven Fishes, it’s sort of an extrapolation of that.”

From Salon • Dec. 14, 2025

The company’s annualized sales—an extrapolation of the next 12 months’ revenue based on recent sales—grew from $100 million to $1 billion this year.

From The Wall Street Journal • Dec. 1, 2025

But it’s an extrapolation of those ethics at the New York Times.

From Slate • Nov. 17, 2025

In 2016, he co-authored an analysis published in The BMJ asserting that medical error is the third leading cause of death in the United States—a claim critics have dismissed as a wild extrapolation.

From Science Magazine • Nov. 25, 2024

I wonder if its social extrapolation is a major reason for attempts at its suppression.

From "Cosmos" by Carl Sagan

Related Words

• calculation
• estimate
• estimation
• forecast