GCSE and A-level students will be given grades based on teacher assessments, after exams were cancelled amid the coronavirus pandemic.
The Government said it is aiming for the calculated grades – which will also take into account their previous achievements – to be awarded to pupils in England by the end of July.
Making the announcement on Friday, Education Secretary Gavin Williamson said these are “extraordinary times” and that exam boards would be working closely with teachers to implement the new approach.
Students will also have options including appealing against their calculated grade, and sitting exams at a later date.
Teaching bodies were largely welcoming of the new guidance, but said more detail will be required in the coming days.
The approach will see exam boards asking teachers to submit judgments about the grades they think their students would have received if exams had gone ahead.
Teachers will have to take into account “a range of evidence and data”, such as mock exam results and other school work, the department said.
This will be combined with information from “other relevant data”, such as pupils’ previous attainment, to calculate their grades.
The calculated grades will be “a best assessment” of the work students have put in, the Government said.
A-level and GCSE grades are usually published in mid-August.
Mr Williamson said: “Cancelling exams is something no Education Secretary would ever want to do, however these are extraordinary times and this measure is a vital but unprecedented step in the country’s efforts to stop the spread of coronavirus.
“My priority now is to ensure no young person faces a barrier when it comes to moving onto the next stage of their lives – whether that’s further or higher education, an apprenticeship or a job.
“I have asked exam boards to work closely with the teachers who know their pupils best to ensure their hard work and dedication is rewarded and fairly recognised.”
The department said this year’s grades will be “indistinguishable from those provided in other years” and would aim to ensure that the distribution of grades follows a similar pattern to previous years, so affected students do not face a “systematic disadvantage”.
It also outlined various options for students and parents who may not be happy with the approach or their calculated grades.
The department said: “If they do not believe the correct process has been followed in their case they will be able to appeal on that basis.
“In addition, if they do not feel their calculated grade reflects their performance, they will have the opportunity to sit an exam at the earliest reasonable opportunity, once schools are open again.
“Students will also have the option to sit their exams in summer 2021.”
As well as academic qualifications, many students will have been due to take exams for vocational courses this summer.
The Government said these vocational qualifications are offered by a wide range of awarding bodies, with different types of assessment, and urged the relevant organisations to “show the maximum possible flexibility and pragmatism to ensure students are not disadvantaged”.
Welcoming the announcement, Nansi Ellis, assistant general secretary of the National Education Union (NEU), said: “Evidence shows teacher-assessed grades are reliable and valid.
“We expect to work closely with Government on further detail to make this as fair as possible for all involved.”
Geoff Barton, general secretary of the Association of School and College Leaders, said the newly announced system “leaves many questions unanswered and will clearly require more detail”.
But he added the union is “confident that Ofqual, the exam boards, schools, and colleges will do everything possible to ensure grades are awarded fairly and consistently in these difficult circumstances”.
The heads of the Russell Group, GuildHE, MillionPlus and University Alliance issued a joint statement confirming that universities will support students by being “flexible and responsive in their admissions processes”.
The statement added: “We want to reassure students who have applied to university, or are thinking of doing so through clearing, that every effort will be made to ensure they are not disadvantaged in any way by the decision not to go ahead with exams this summer.”
Meanwhile, Birmingham City University has said it will provide unconditional university places for hundreds of applicants based on their GCSE grades.
It said it had already begun to offer unconditional places to all students who have been made a conditional offer, and already have five or more GCSEs at Grade 4 or above.
England’s exams regulator Ofqual said it welcomed the “information and clarity” the Government has provided, and said more detail on the process will be given in the next few days.
It said in a statement: “We are working tirelessly to support students affected by these unprecedented and difficult circumstances and to develop, quickly, a fair and consistent process.
“We know that schools and colleges urgently need to know what they will need to do, and when.”