Thousands of schools were deemed as "requiring improvement" following the introduction of Ofsted's new system which saw the "satisfactory" rating scrapped.
Almost a third of schools were coasting and were at risk of facing sanctions if they did not improve, according to figures released on Monday.
Schools can be rated outstanding, good, requires improvement or inadequate under the new rules, which the Ofsted chief insisted were a success. In a speech to headteachers, Sir Michael Wilshaw is due to say the changes have "galvanised" schools into raising standards.
Wilshaw is to insist England's schools system is making "genuine and radical" advances, and will say the major overhaul of inspections was not meant to inject fear, but to signal that "mediocrity" is unacceptable.
The figures, which were published on Monday, reveal the state of England's school system. The data will show the proportion of schools in each of the inspectorate's four categories - outstanding, good, requires improvement and inadequate.
Sir Michael introduced a revamped inspection system last September and the statistics will show how schools who have been inspected under the new regime have performed.
The major changes included cutting the amount of notice schools were given of an inspection, and replacing the old satisfactory rating with "requires improvement".
Under the new system, schools judged to require improvement at two consecutive inspections and who are still not providing a good education at the third, face being placed in special measures.
Sir Michael has previously said the move will further challenge schools to give pupils a good education, but it has caused upset among headteachers' unions concerned it will leave more schools in special measures.
In a speech to outstanding headteachers from across the North West in Manchester, Sir Michael is expected to say: "Thanks to the work of dedicated teachers and outstanding headteachers up and down the country, England's school system is making some genuine and radical advances."
He is also expected to tell them: "Ofsted wants to back those leaders of our schools who want to do the right thing, even when their schools are not doing particularly well.
"I make no apology as chief inspector for raising the bar on school standards - no apology for replacing 'satisfactory' with 'requires improvement'
"This was not about injecting fear into the system, but signalling quite clearly that mediocrity, which the term 'satisfactory' denoted, is no longer acceptable."
Figures published earlier this year showed that in the first two terms of the new inspection system, of the more than 5,000 schools inspected, almost half (48%) improved their rating, 42% stayed the same and just over one in 10 (11%) declined.
Nationally, more than three quarters of schools (79%) were rated as good or outstanding at their last inspection.