What Percentage Is Each Letter Grade? A Teacher Breaks Down Common K-12 Grading Scales
The crinkle of Lila’s math test cut through the hum of the dishwasher last Tuesday. She pushed the crumpled paper across the kitchen counter, half a pack of Goldfish crackers spilled next to her half-empty apple juice box. “Ms. Henderson gave me a B+,” she said. “What percent is that? Does that mean I got 12 questions wrong? Jake got an A on his test over at the middle school, and he told me he only got a 92. That doesn’t add up.”
I’m a 7th grade teacher with 12 years in the classroom, and I serve on our district’s grading policy committee. Even so, I paused. My 10-year-old just started getting letter grades on her tests this year, and I’d forgotten how confusing the mismatch between percentages and letters is for everyone, kids and parents alike.
Last semester alone, I got five emails from parents asking the exact same question: what percentage lines up with which letter grade? One parent panicked because her 8th grader had an 89.5 that I’d marked as an A-, but the private high school they were applying to counted any score 90 and above as an A for honors eligibility. Another dad wanted to calculate his son’s GPA early for college, and he couldn’t figure out why an A at our school was different from an A at the Catholic school 15 minutes down the road.
The biggest source of confusion is that there’s no national universal standard for converting percentages to letter grades. Every district, every school, even some individual teachers set their own cutoffs. That said, about 80% of public K-12 schools in the U.S. use a standard 10-point unweighted scale that looks like this: A+ is 97 to 100, A is 93 to 96, A- is 90 to 92, B+ is 87 to 89, B is 83 to 86, B- is 80 to 82, C+ is 77 to 79, C is 73 to 76, C- is 70 to 72, D+ is 67 to 69, D is 63 to 66, D- is 60 to 62, and anything below 60 is an F.
Even that common scale has regular variations. Plenty of schools don’t give out A+ at all, so they start A at 93 and go up to 100, skipping the extra plus. Some smaller private schools use a tighter 7-point scale, where A starts at 94, A- at 90, B+ at 87, and so on, moving cutoffs up a few points. Weighted classes for AP, honors, or IB don’t usually change the percentage to letter conversion—they just change the GPA value when schools calculate class rank, so an A in an AP class counts for more points toward your final GPA than an A in a regular class. Colleges can have even bigger differences: many don’t use minus grades at all, so any score from 90 to 100 is just an A, no plus or minus attached. Some even adjust cutoffs for different departments.
When Lila saw that her 88% was a solid B+ per our district’s scale, she relaxed a little. She’d been worried B+ meant she’d failed half the test, which is a common misconception I see all the time with kids just getting used to letter grades. I explained that Jake’s A at the middle school came from their school’s policy of rounding up any score 92 and above to an A, which is why his 92 was an A instead of an A- like it would be at our elementary.
Over the years, I’ve picked up a few simple things that make this less stressful for everyone, instead of guessing from old memory or random online charts. First, always check your own school’s course syllabus or student handbook first. 99% of districts post their full grading scale online on the parent portal now, so it takes two minutes to pull up instead of relying on what you remember from high school, or what your neighbor says their kid’s school does.
Second, if your kid is applying to a new program, high school, or college and you need to convert their letters to percentages for an application, just send a quick email to the admissions office asking their conversion policy. It’s way faster than guessing, and it avoids the last minute panic when you find out they use a different scale than you expected. Last year, I helped a parent sort this out for a private high school application, and we found out their cutoffs were 5 points lower than our district’s, which changed her kid’s eligibility for a scholarship we would have missed if we’d just used our local scale.
Third, don’t waste energy fighting over a 0.5% difference unless it actually changes something for your kid. I’ve had parents spend hours arguing over an 89.4 that got marked as a B+ instead of an A-, when the kid already had the GPA they needed for honors, and the difference would only change their overall GPA by 0.03, which doesn’t move the needle for any admissions or eligibility. It’s easy to get hung up on the perfect letter, but most of the time, tiny differences don’t matter long term.
Lila ended up doing the optional extra credit problem that weekend, and Ms. Henderson bumped her up to an A-. She taped the test to the fridge next to her soccer trophy, and hasn’t mentioned it since. I still get at least two questions a month about what percentage lines up with what letter, and I always tell people the same thing: start with your own school’s policy, don’t assume it’s the same everywhere, and only stress about the numbers that actually change something. It’s not a trick question, it just takes a minute of looking up the right details for your kid.
Please indicate: Thinking In Educating » What Percentage Is Each Letter Grade