Estimate / Forecast / Projection
UsageAn estimate infers a population value from sample data for a previous reference period; a forecast states an expected future value; a projection shows a conditional future value under stated assumptions.
Estimate
Use when
You are inferring a population value for a previous reference period from data collected from a sample.
Example
“The survey estimate puts service uptake in the previous quarter at 62%.”
Forecast
Use when
You are stating what you expect is likely to happen, based on evidence and assumptions about future events.
Example
“The finance team forecasts a 4% increase in operating costs next year.”
Projection
Use when
You are showing what would happen if a stated set of assumptions or scenarios holds.
Example
“Under the high-demand scenario, applications are projected to reach 80,000 by 2030.”
Quick check
projection presented as a prediction, forecast without assumptions, estimate without a reference period
Usage note
Disciplines define these terms differently. State the reference period, evidence, assumptions and uncertainty instead of relying on the label alone.