The phrase "a grade off" is correct and usable in written English.
It can be used in contexts where you are discussing a reduction in a grade or score, often in an academic setting.
Example: "If you miss the deadline, you will receive a grade off for your assignment."
Alternatives: "a point deducted" or "a mark taken off".
OC: It took about a full grade off — you know, a grade value off of my fall grades because I was so dedicated to the band.
When I return their letters, I don't just give them a grade based off their grammar.
Episode Grade: A- (Points off for the scene where Bill and Don Embry talk really, really specifically about the way they control their wives. It's like they're saying, "Hey audience! Here's some forced insight into the writers' perspective on our world!") For more reviews and videos, go to The Critical Condition.
And the kinds of rewards that are mentioned, rewards that will be given — lifetime, if you bump off a Grade A leader.
Music critic Robert Christgau gave the album a positive (A) grade believing that Off the Wall was "the dance groove of the year" and the album presented Jackson as a grown up.
She had a 2-mm step-off with a grade III chondral defect over the medial tibial plateau and a grade III chondral defect on the femoral condyle facing the fracture.
For example, the multi-million pound refurbishment of Killeavy Castle in south Armagh is taking a grade A listed structure off the at-risk register and transforming it in to a spa hotel.
They take a set of criteria and assign a grade to each politician based off of inputted data.
When she delivers a Grade-A vitriolic tell-off to Hank, and then hits him with her walking stick (I think in between his legs) and forces him to leave the room (opening and shutting the door with her mind, no less), I was practically cheering.
The review, by Timothy Noah of Politico, starts off with a grade-school level taunt: "If space aliens were to land a flying saucer on the Capitol's South Lawn, one question they might ask is: Wherever did you get the idea that cutting taxes would increase revenue?" That's mediocre rhetoric, talk of space aliens.
