extrapolate
/ɪkˈstræp.ə.leɪt/To use known facts, data, or trends to make a reasonable guess about something that is unknown or has not happened yet. You go beyond what you directly observe, but you base your conclusion on existing patterns.
- Scientists extrapolated future sea levels from decades of temperature records.
- We can extrapolate from these results that demand will rise next year.
- It is risky to extrapolate findings from one small study to an entire population.
Adinary Nuance
Extrapolate is often placed next to infer, deduce, and project, but each does something distinct. To infer is to draw a conclusion from evidence already in front of you — the reasoning stays within what you can see. To extrapolate goes a step further: you take an established pattern or trend and deliberately extend it beyond the range of your current data, often into the future or to a wider group. Deduce relies on logical rules rather than data patterns, making it a different kind of reasoning entirely. In academic writing, use project when forecasting specific numbers (revenue, population); use extrapolate when you want to emphasize the analytical process of stretching a known trend outward.
In other languages
- Vietnamese
- Ngoại suy
- Spanish
- Extrapolar
- Chinese
- 外推
- Japanese
- 外挿する
- Korean
- 외삽하다
Etymology
From Latin 'extra' (outside, beyond) combined with 'polire' (to smooth or polish), the word entered English as a mathematical term in the 1870s. It later broadened in meaning to describe any reasoned extension of known information into unknown territory.
Common phrases
Synonyms
Related words
Frequently asked questions
- Is 'extrapolate' a formal word?
- Yes, it is primarily a formal, academic word common in research, scientific reports, and IELTS Task 1 writing. In casual conversation, most people would just say 'predict' or 'guess' instead.
- What is the difference between 'extrapolate' and 'interpolate'?
- Both come from mathematics and statistics. 'Interpolate' means estimating a value within a known data range. 'Extrapolate' means estimating beyond that known range. For example, using data from 2000–2020 to estimate 2030 figures is extrapolation, not interpolation.
- Can I use 'extrapolate' in an IELTS essay?
- Yes, and used correctly it signals strong academic vocabulary. It works well in Task 1 when describing trends: 'Extrapolating from the graph, one can predict that sales will continue to rise.' Make sure your context involves actual data or trends.
- What is the noun form of 'extrapolate'?
- The noun is 'extrapolation.' You might write: 'This extrapolation is based on five years of observed data.' The adjective form is 'extrapolated,' as in 'extrapolated figures.'