The phrase "actual extent" is correct and usable in written English.
It can be used when discussing the true or real scope or range of something, often in contexts like research, analysis, or measurement.
Example: "The study aimed to determine the actual extent of the environmental impact caused by the new construction project."
Alternatives: "real scope" or "true range".
It's an issue which is easy to blow up beyond its actual extent.
Yet the actual extent of commercial surveillance on Facebook remains murky.
Consequently, the actual extent of youth violence in London cannot be accurately established.
The actual extent of the "secrecy" of the family courts has been poorly understood.
The ceremony and self-celebration notwithstanding, the actual extent of the blogging community's power is still unclear.
He added: "It is crucial that scientists and the public continue in-water monitoring to track the actual extent and severity of the bleaching it causes".
That is why it is so important that five Sunni-dominated states have signed up for the attacks against Isis, whatever the actual extent of their participation.
Official information was being released slowly, leaving the actual extent of the damage unclear after the quake, which had a preliminary magnitude of 6.8.
But the chief inspector warned that the Home Office had not yet established the actual extent of sham marriage immigration abuse in Britain despite recent work to set up a new intelligence system.
But the intelligence community was deeply divided over the actual extent of Iraq's weapons development; the question of Russia's responsibility for cyberattacks in the 2016 election has produced no such tumult.
Though the F.B.I. estimates that the value of this black market is as much as $6 billion a year, we do not really know the actual extent of the trade in illicitly obtained antiquities.
