Most large US school districts grade on a 10-point scale. We checked the official high school grading policies of the 50 largest public school districts and found a published scale for 32. Of those, 20 use A = 90%, B = 80%, C = 70% and D = 60%. The rest use a 93% A, a 70% minimum pass, or no D grade at all.
- 20 of 32 (62%) use the 10-point scale (90/80/70/60). 12 of these are Florida districts, where state law sets the scale.
- 5 use a stricter plus/minus scale with an A starting at 93% (Fairfax, Philadelphia, Denver, Loudoun) or 92% (Prince William).
- 7 make 70% the lowest passing grade, mostly in Texas and Georgia. Houston, Gwinnett and Fort Bend have no D grade.
- 6 districts publish a 50% grade floor, so a missing assignment does not count as a zero.
Grading Scale Types at a Glance
Based on 32 districts with a published high school scale. Districts where we could not find an official percent-to-letter scale are not counted.
Grading Scales by District
Ranks are by student enrollment. Each source link opens the official document we read: either the district’s own policy or handbook, or the state rule the district follows.
| Rank | District | State | A from | B from | C from | D from | Notes | Source |
|---|---|---|---|---|---|---|---|---|
| 4 | Miami-Dade County Public Schools | FL | 90% | 80% | 70% | 60% | – | District |
| 5 | Clark County School District | NV | 90% | 80% | 70% | 60% | 50% floor | District |
| 6 | Broward County Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 7 | Hillsborough County Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 8 | Orange County Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 9 | Houston ISD | TX | 90% | 80% | 70% | – | – | District |
| 10 | School District of Palm Beach County | FL | 90% | 80% | 70% | 60% | – | District |
| 11 | Gwinnett County Public Schools | GA | 90% | 80% | 70% | – | – | District |
| 12 | Fairfax County Public Schools | VA | 93% | 83% | 73% | 60% | +/− grades, 50% floor | District |
| 14 | Wake County Public School System | NC | 90% | 80% | 70% | 60% | – | District |
| 15 | Montgomery County Public Schools | MD | 89.5% | 79.5% | 69.5% | 59.5% | 50% floor, rounds at .5 | District |
| 17 | Charlotte-Mecklenburg Schools | NC | 90% | 80% | 70% | 60% | 50% floor | State rule |
| 18 | Duval County Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 19 | Prince George’s County Public Schools | MD | 90% | 80% | 70% | 60% | 50% floor | District |
| 20 | School District of Philadelphia | PA | 93% | 83% | 73% | 60% | +/− grades, 50% floor | District |
| 21 | Cypress-Fairbanks ISD | TX | 90% | 80% | 75% | 70% | numeric grades | District |
| 23 | Cobb County School District | GA | 90% | 80% | 74% | 70% | – | District |
| 24 | Memphis-Shelby County Schools | TN | 90% | 80% | 70% | 60% | – | State rule |
| 25 | Polk County Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 26 | Northside ISD | TX | 90% | 80% | 75% | 70% | – | District |
| 27 | Lee County School District | FL | 90% | 80% | 70% | 60% | – | State rule |
| 28 | Pinellas County Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 33 | Prince William County Public Schools | VA | 92% | 82% | 72% | 62% | +/− grades | District |
| 34 | Denver Public Schools | CO | 93% | 83% | 73% | 60% | +/− grades | District |
| 35 | Katy ISD | TX | 90% | 80% | 75% | 70% | – | District |
| 39 | Pasco County Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 40 | Loudoun County Public Schools | VA | 93% | 83% | 73% | 63% | +/− grades | District |
| 41 | Metropolitan Nashville Public Schools (Davidson County) | TN | 90% | 80% | 70% | 60% | – | State rule |
| 43 | Fort Bend ISD | TX | 90% | 80% | 70% | – | – | District |
| 44 | Greenville County Schools | SC | 90% | 80% | 70% | 60% | – | State rule |
| 49 | Brevard Public Schools | FL | 90% | 80% | 70% | 60% | – | State rule |
| 50 | Osceola County School District | FL | 90% | 80% | 70% | 60% | – | State rule |
What This Means for Students
The same percentage can earn a different letter grade in different schools. A 92% is an A- in Fairfax but an A in Prince William County, and a 65% passes in Miami-Dade but fails in Houston. Before you work out what you need on a test, check your own school’s scale. Our grading scale guide compares the common versions, and the grading chart converts any percentage to a letter.
Use the test grade calculator to turn a score into a percentage, the final grade calculator to see what you need on the final, and the high school GPA calculator to see how weighted honors and AP grades change your GPA.
What This Means for Teachers
Teachers usually cannot change the scale, but they control how tests are scored. The easy grader shows the percentage for every number of wrong answers, and the grade curve calculator curves a whole class’s scores. Both can also be added to a class website from our free calculator widgets page.
Methodology
We started from the 50 largest US public school districts by enrollment (NCES Digest of Education Statistics 2022, Table 215.30, fall 2021). For each district we looked for the official high school letter-grade scale in board policy, the student handbook, the course catalog or the state rule the district follows. We recorded the lowest percentage for A, B, C and D. We only counted a scale when we could read it in an official district or state document. Research was done in November 2026; policies can change, so check your school’s current handbook.
Frequently Asked Questions
What is the most common grading scale in US high schools?
In this study, 20 of 32 large districts use the 10-point scale: A from 90%, B from 80%, C from 70% and D from 60%. Florida, North Carolina, Tennessee and South Carolina set this scale for every district in the state.
Is a 92% an A or an A-?
It depends on the school. On a 10-point scale with plus/minus grades, 92% is an A-. In Fairfax, Philadelphia, Denver and Loudoun, where an A starts at 93%, 92% is also an A-. In Prince William County, an A starts at 92%, so 92% is an A.
Is 70 a passing grade?
Yes, in every district in this study. In Northside, Katy, Cypress-Fairbanks and Cobb, 70% is the lowest passing grade. In Houston, Gwinnett and Fort Bend, there is no D, so anything below 70% is an F.
What is a 50% grade floor?
Some districts do not record a grade below 50% for work that was attempted, so one zero cannot sink a whole term. 6 districts in this study publish a 50% floor, including Clark County, Fairfax and Philadelphia.
Can I use this data?
Yes. You can quote or chart the findings with a link to this page as the source. Each row links to the official district or state document it comes from.