Inspectors could begin issuing individual grades for nurseries and reception classes from September 2014 if the plans go ahead.
In a consultation, Ofsted said the change to the inspection regime was necessary to reflect the 'distinctive nature' of Early Years Foundation Stage (EYFS) teaching.
It outlined plans for inspectors to use a separate set of evaluation criteria for early years, which focused on achievement, quality of teaching, behaviour and safety, and leadership and management.
Inspectors would be required to include a paragraph evaluating EYFS provision in their school inspection report, and take account of the separate judgement when evaluating the overall effectiveness of the school.
The report states, 'These changes would assist parents in making better-informed choices when deciding on the first steps in their children’s education.'
Pre-school Learning Alliance chief executive Neil Leitch said he was pleased Ofsted was considering a separate, graded judgement.
But he warned the criteria outlined in the consultation would isolate school-based provision from non-school sited early education providers.
'The Alliance is concerned that the proposed criteria for inspection which focuses on achievement, the quality of the teaching, behaviour and safety, leadership and management, differ from those in the wider early years sector,' said Mr Leitch.
'This is likely to set school-based early years provision apart from other services and make a comparison of performance difficult.
'Ofsted’s role is to assess the effectiveness of the delivery of the EYFS, so its judgements should be made against a consistent criteria to assist benchmarking and ensure the overall fairness of the process across all types of childcare, regardless of where the provision is delivered.'
National Day Nurseries Association (NDNA) chief executive Purnima Tanuku said Ofsted’s proposed changes did not go far enough.
'While the proposal to have a separate judgment for early years in schools is an improvement on the current situation where there can be little mention of early years in a school's report, it still means parents of young children will have very limited information about a school's provision,' she said.
'The proposed paragraph in school reports about early years is in no way a level playing field with a full inspection and report on standalone early years provision. It also gives local authorities making decisions about early years funding little to go on.
'NDNA believes schools should have to register and be inspected as early years settings so all children have the benefit of the same level of protection wherever they take up their early education.
'This is particularly critical for under-threes and we're urging government to rethink its plans for legislation that will allow schools to take two-year-olds without having to register separately with Ofsted.'
Education union the Association of Teachers and Lecturers (ALT) general secretary Mary Bousted criticised the timing of the announcement.
'Ofsted needs to stop changing the format of its inspections every time it thinks of something new to do,” she said.
'We are not particularly opposed to separate judgements for early years, but ask why Ofsted is not introducing this at the same time as all the other recent and planned changes.
'These constant changes make it incredibly hard for teachers and heads to know what Ofsted is looking for, lead to parents losing faith in reports about their local schools, undermine this form of school accountability and give the public little confidence that Ofsted knows what it is doing.'
Ms Bousted added that Ofsted needed to insure its inspectors had appropriate expertise and experience to inspect early education.
'Too often early years teachers find themselves being told what to do by inspectors unfamiliar with teaching and developing young children,' she said.
The consultation also seeks opinions on plans for Ofsted to separately grade school sixth forms, and is open for responses until 13 May 2014.