Codsall Community High School student Monica Lewis has arranged the protest which will take place on Monday at 1pm and students will walk to Gavin Williamson MP's office from the school site.
Education Secretary Gavin Williamson had made a “triple lock” commitment that students could use the highest result out of their teacher’s predictions, their mock exam or sitting the full exam in the autumn.
On Saturday Ofqual published its criteria for appeals based on mock exams, saying if the result was higher than the teacher’s prediction then the latter would count.
But hours later the regulator said the policy was “being reviewed” by its board and further information would be released “in due course”.
Monica said: "I received my A-level results on August 13 and was left devastated to find I had been downgraded from my predicted grades due to the use of the algorithm.
"For this reason, I am setting up a local protest like many other students across the country. The protest will be held on August 17, and will start at 1pm.
"It will start at Codsall Community High School with a march down to Gavin Williamson’s office in Codsall.
"We hope this will have an impact on the education security’s decision to make a U-turn with the way our results have been calculated, and will encourage the government to fix this appalling outcome."