Education
Teacher Grading Calculator
Enter student scores to get class average, median, mode, standard deviation, grade distribution, and curve suggestions.
Student Scores
Grade Boundaries (%)
Enter student scores to see class statistics and grade distribution
How is this calculated?
Mean (Average) = Σ scores / n
Median = middle value when sorted (avg of two middle if n is even)
Mode = most frequently occurring score(s)
Standard Deviation = √[Σ(xi - mean)² / (n - 1)] (sample SD)
Grade Distribution = count scores in each boundary range
Curve Suggestion = (Target Average - Actual Average) points added
Target: 78% (typical curve target)FAQ
Frequently asked questions about grading
How does grading on a curve work?
Curving adjusts scores so the class average meets a target (often 75-80%). The simplest method adds a fixed number of points to all scores. More complex curves use standard deviations to redistribute grades.
What is a good class average?
Most institutions consider 70-80% a healthy class average. Below 60% suggests the assessment was too difficult or instruction needs adjustment. Above 90% may indicate the assessment was too easy.
How is standard deviation useful for grading?
Standard deviation shows score spread. A low SD (5-10) means students performed similarly. A high SD (15+) indicates a wide range of performance, which may warrant curved grading or differentiated instruction.
What are typical grade boundaries?
Common US scale: A = 90-100%, B = 80-89%, C = 70-79%, D = 60-69%, F = below 60%. Some institutions use plus/minus grades (A+, A, A-) with 3-4 point ranges.
Can I paste scores from a spreadsheet?
Yes. Enter scores separated by commas, spaces, or line breaks. You can copy a column from Excel or Google Sheets and paste it directly into the scores field.
How many students are needed for meaningful statistics?
Statistical measures become more reliable with larger samples. 10+ students gives reasonable averages. 30+ students makes standard deviation and distribution analysis meaningful.