What Percentage Is Each Letter Grade? A Teacher’s Clear Breakdown for Parents
Last night, I was standing at the kitchen counter packing my 10-year-old’s lunch for the next day, half-listening to him ramble about soccer practice, when he dumped his backpack upside down on the sticky linoleum and pulled out his first quarter progress report. He held it up to me, squinting at the math line. “I got a B- here,” he said. “What percentage is that even? Is that like, a 70? Did I fail the last test?”
Before I could answer, my work phone pinged with a text from a parent of my 8th grade student. “Hey, can I ask a quick question? Lila got an A- in language arts, and we’re starting to map out her high school GPA for college apps. What percentage is an A- anyway, and what’s that for GPA?”
I stirred my cold coffee that had been sitting since 6 PM and laughed a little. This question comes up at least once a month, between being a mom and a middle school language arts teacher. Most of us don’t have a grading scale memorized, especially since schools shifted to the plus-minus letter system over the last 20 years. If you grew up with just straight A, B, C, D, F where an A was anything over 90, the new plus and minus grades can feel like a whole new language.
Over the 12 years I’ve been teaching, I’ve seen a handful of different scales, but the one most public schools across the US use right now is pretty consistent. Let me lay it out plain, the way I explain it to parents: A+ is almost always 97 to 100 percent, A is 93 to 96, and A- is 90 to 92. Then B+ is 87 to 89, B is 83 to 86, B- is 80 to 82. C+ hits at 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 any percentage below 60 is an F. Some smaller schools skip plus and minus for Ds, so D just covers 60 to 69, and anything below 60 is F— that’s the only common variation I see on this standard scale.
For people who also need the GPA conversion that most high schools and colleges use, that breaks down to a 4.0 scale like this: A+ is usually 4.0 (some weighted honors classes bump it to 4.3, but that’s a separate conversation), A is 4.0, A- is 3.7, B+ is 3.3, B is 3.0, B- is 2.7, C+ is 2.3, C is 2.0, C- is 1.7, D+ is 1.3, D is 1.0, and F is 0.
I told my son his B- meant he was somewhere between 80 and 82 percent, and he nodded. That matched the 81 he got on his last unit test, he said— he just forgot what the letter translated to. I texted the parent back the same breakdown, and explained that Lila’s A- was a 91 percent, which translated to a 3.7 GPA, that it was still an excellent score, nothing to worry about. She wrote back 10 minutes later saying she had no idea an A- was still in the 90s, she thought it dropped down into the 80s. That’s the most common mistake I see parents make.
Last semester, I had a parent come in for a conference nearly tense with worry because her son got three A- grades on his progress report. She was convinced that would keep him out of the state university he wanted to go to. When we walked through the scale together, she realized all three A- were 90 to 92 percent, that added up to a 3.7 unweighted GPA, which is well above the average incoming GPA at that school. She just associated the minus with a lower grade than it actually is, because she grew up with a different scale.
The thing I tell every parent who asks is that the scale I laid out is the most common, but it’s not universal. Some private schools shift the numbers a little, some still use the old straight letter scale without any plus or minus, where an A is 90 to 100, B is 80 to 89, and so on. That’s why the easiest thing you can do right now, if you have a kid bringing home report cards, is pull up your school district’s website. 99% of districts post their official grading scale right on the parent resources page, and you can just bookmark it on your phone. Next time a progress report comes out, you can pull it up in 10 seconds instead of scrolling through conflicting google results. If you can’t find it there, just shoot a quick email to your kid’s homeroom teacher— most will send you a copy in a day.
I walked my son over to the fridge, where I taped a copy of his elementary school’s grading scale last year, and he pointed out the B- line to confirm. Then he stuffed the progress report back in his backpack and asked for a chocolate chip cookie before bed. I got one out for him, and leaned back against the counter. Grades are just a rough snapshot of how a kid did on a set of assignments over a few months, they don’t tell you anything about how curious they are or how hard they tried, but it’s normal to want to know what the letters actually mean. Uncertainty about the numbers is what makes parents panic over a grade that’s totally fine.
I still haven’t bookmarked the new middle school grading scale on my phone, even after last night. I’ll do it this weekend, when I’m sitting waiting for my son’s practice to end. For now, I’ve got the common scale memorized from answering so many questions, and that’s enough to get by.
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