Equal Interval Grading
Mr. Mike Emery
Assistant Principal
Robert E. Fitch High School
Equal Interval Grading Scale
Traditional 5 Point Scale PowerSchool
Grade
Grade
Percentage
90-100
80-89
70-79
60-69
0-59
4.0-5.0
3.0-3.9
2.0-2.9
1.0-1.9
0-.9
Letter
Grade
A
B
C
D
F
Traditional Grading
• Example:
• Student A earns what is traditionally an 80, 80, 81,
74, and a 30.
• Student A traditional average : 69,
Letter Grade = D+
• Student B earns what is traditionally an 90, 90, 91,
84, and a 65.
• Student B traditional average : 84,
Letter Grade = B
0-5 Equal Interval Grading
• Student A earns 80, 80, 81, 74, and a 30.
• Teacher enters 3.0, 3.0, 3.1, 2.4, and .5 into
PowerSchool
• PowerSchool finds the average of those 5
numbers: 2.4
• Student B earns 90, 90, 91, 84, and a 65.
• Teacher enters 4.0, 4.0, 4.1, 3.4, and 1.5 into
PowerSchool
• PowerSchool finds the average of those 5
numbers: 3.4
0-5 Percentages
• Student C receives a traditional 90 (A-).
• In 0-5 grading this would be a 4.0
• PowerSchool takes the 4.0 and divides by 5
(because 5 is the highest grade you can get)
and calculates 80%.
• This student would receive a B- if we left
PowerSchool alone.
• So we created different percents for the 0-5
scale.
0-5 Percents
• For example: We want the 4 to be an A- so we
made the A range run from 80-100%
• We want 3 to be a B- so we made the B range
run from 60-79….
• And so on
Traditional
Grade
5 Point Scale
Grade
PowerSchool
Percentage
Letter Grade
90-100
80-89
70-79
60-69
0-59
4.0-5.0
3.0-3.9
2.0-2.9
1.0-1.9
0-.9
80-100
60-79
40-59
20-39
0-19
A
B
C
D
F
• We know at this point that Student A has a C average
(see the chart above).
• However, PowerSchool cannot just assign the grade at
this point. It needs to convert to a percentage.
• PowerSchool takes the 2.4 and divides by 5 to get 48%.
• PowerSchool converts the 48% to a letter grade (C),
using the chart above.