How many B's are too many?

Since you only have 1 full year of grades from 9th grade that reflects your GPA, 1 "B" is not that important right now. There are plenty of applicants to T20 schools that had had more than 1 B, some 2 or 3 B's. What is more important about your transcript when you submit it with your college application are the following: 1.) Does your transcript reflect you tried your best? 2.) Does your transcript reflect that you challenged yourself with the most challenging classes, 3.) Does your transcript show a clear upward trend vs a downward trend or a flat line of improvement and lastly which is difficult for some to understand 4.) Does your transcript show that you took risks and did everything to correct the gaps or faux pas on your academic record? To me, the last part is very important if you have Bs on your transcript. If you have a B in a STEM class like Algebra 2 or Chemistry and you are expected to take 3 more years of math and 3 more years of science, you have a big problem right? Why? Because Math just gets harder and AP Chem or AP Physics is harder than plain jane Chem. So you have to be strategic about this over the next 2 years. If you can figure out a way to take a dual enrollment class at a community college in STEM or an online college course over the summer and grind on that like twice as hard as when you got the B, it will show that you took risks, challenged yourself and overcame this deficit with flying colors. Now very few people see failure as an opportunity to pick up the pieces to get a better score and something harder but if you can do this and have the mindset to attempt this and succeed, it will pay in dividends when you are ready to apply to a T20 college. Otherwise, you will be applying against other kids in your school that have perfect grades and perfect test scores to the same schools.

I did this and it was a lot of work. I have 1 B in Algebra 2 on my transcript. But last summer I took a college Calculus Course at got an A and 3 college credits. I skipped having to take AP Calc online with my peers and I already earned the 3 college credits so all I have to do is transfer them and use them to place in a higher math class in college freshman year. Although I signed up for the AP test in Calc, I'm only doing it to see if I can get a 5 in it for myself. It has no bearing on my college admissions acceptance.

Good luck with your decision about what to do.

There's never a magic formula for how many Bs are okay. It also really depends on the school and other parts of your application. If I were to make a guess, however, your unweighted GPA should at least be a 3.75 cumulative for you to be competitive(again this all depends). If you are taking a lot of AP/IB classes, a couple of Bs shouldn't be too harmful to your application. You could write about how due to Covid-19 you had to take online classes and couldn't really focus on school with your family being noisy 24-7 (or something like that).