Converting percentages to letter grades is a fundamental task in homeschool record-keeping. This chart provides the two most commonly used grading scales in US education, with and without plus/minus modifications.
Standard scale (93/85/77/70)
| Percentage | Letter | GPA |
|---|
| 97-100 | A+ | 4.0 |
| 93-96 | A | 4.0 |
| 90-92 | A- | 3.7 |
| 87-89 | B+ | 3.3 |
| 85-86 | B | 3.0 |
| 82-84 | B- | 2.7 |
| 79-81 | C+ | 2.3 |
| 77-78 | C | 2.0 |
| 74-76 | C- | 1.7 |
| 72-73 | D+ | 1.3 |
| 70-71 | D | 1.0 |
| 0-69 | F | 0.0 |
Alternate scale (90/80/70/60)
| Percentage | Letter | GPA |
|---|
| 97-100 | A+ | 4.0 |
| 93-96 | A | 4.0 |
| 90-92 | A- | 3.7 |
| 87-89 | B+ | 3.3 |
| 83-86 | B | 3.0 |
| 80-82 | B- | 2.7 |
| 77-79 | C+ | 2.3 |
| 73-76 | C | 2.0 |
| 70-72 | C- | 1.7 |
| 67-69 | D+ | 1.3 |
| 60-66 | D | 1.0 |
| 0-59 | F | 0.0 |
The standard scale is more rigorous: an 89% earns a B+ rather than an A-. The alternate scale is used in many southern and midwestern states. Choose one and apply it consistently across all courses on your transcript.
Include a grading scale legend on every transcript and report card. A one-line note such as "Standard scale: A=93-100, B=85-92, C=77-84, D=70-76" ensures reviewers interpret grades correctly.
Which grading scale is more common in homeschooling?
Both are widely used. The standard 93-scale is more common in northeastern states and in many published curricula. The alternate 90-scale is more common in southern states. Neither is more legitimate than the other.
Can I create my own custom grading scale?
You can, but it is not recommended. Using a widely recognized scale makes your transcript more credible and easier for admissions officers to interpret. If you must deviate, document your scale clearly.
How do I convert a curriculum percentage to my scale?
Apply your chosen scale directly. If a curriculum reports 88% and your scale defines B+ as 87-89, the grade is B+. Do not convert between scales unless the curriculum specifies which scale it uses.
Should A+ count as 4.0 or 4.3 on the GPA?
Most homeschool families cap A+ at 4.0 for unweighted GPA. Some schools use 4.3. Either approach is acceptable, but capping at 4.0 is more conservative and widely understood. Document your choice.
How do I handle grades from external providers?
Accept the grade as reported by the external provider (online school, co-op, tutor) and convert it to your grading scale for the transcript. Note the external provider in the course description supplement.