A report by the Scottish Council Of Independent Schools (SCIS) says the value of the sector to the wider economy is £446 million a year and more than 11,200 jobs.
An accompanying commentary written by John Edward, director of SCIS, attacked the "old assumptions" about the privileged socio-economic background of private pupils in the wake of tough new charities legislation.
In 2012, the Office Of The Scottish Charity Regulator launched an investigation into the charitable status of private schools - a status which exempts them from paying millions of pounds in rates and tax.
The inquiry looked at the wider public benefit schools were providing, as well as their fee levels and the number of means-tested bursaries on offer.
Although some schools were told to improve financial assistance for poorer pupils, nearly all schools have now passed the charities test.
Mr Edward highlighted the regulator's figures, which show more than 400 poorer pupils in Scotland receive a 100% remission on their school fees, in addition to an expansion in means-tested bursaries.
His report states: "No group in Scotland is better able to demonstrate their compliance with the requirements to meet charitable purposes.
"Independent schools are charities because they fulfil purposes for the public benefit ... they are no different to other educational charities, such as further education colleges or universities.
"Means-tested financial assistance now far outstrips any taxation rates that follow from charitable status."
Mr Edward said now was an appropriate moment to move away from narrowly-focused preconceptions about a lack of diversity at private schools. He added: "They are not a distinct group seeking to be set apart by the way they are educated.
"It is a striking characteristic of the debate on charitable status, for example, and widening of access through means-tested bursaries, that old and unrevised assumptions about the socio-economic background of pupils remain.
"Scottish schools and families have met the challenge presented to them, a policy outcome that should be a matter of note for legislators and of recognition of the efforts made."
Meanwhile, the separate economic assessment report found the wider contribution of private schools to the competitiveness of the Scottish economy - including what schools and staff spend on goods and services - totalled £446m.
This included exports worth almost £28m per year and a contribution of more than £263m a year to public finances.
In addition, the report says the sector generates a number of wider benefits, including supporting the Scottish university sector, developing a high calibre workforce and encouraging inward investment.
The conclusion states: "This report has demonstrated the Scottish independent schools sector generates substantial benefits for the Scottish economy.
"In addition, this report has also found evidence the sector generates a number of wider economic benefits that cannot be fully quantified."
The report was produced by BiGGAR Economics, an independent economic consultancy based near Edinburgh, which has undertaken similar assessments for Edinburgh, Heriot Watt, St Andrews, Aberdeen, Robert Gordon and Glasgow Caledonian universities.