Attendance Percentage Calculator

Use this attendance percentage calculator to quickly work out your current attendance, see how many days or classes you’ve missed, and check how many more you can miss while staying above your target. It works for school, college, and homeschool attendance.

How to Use the School Attendance Calculator

The calculator has three options depending on what you need.

Attendance % works out your current attendance from the number of days or classes held and attended. Add your target percentage and it will also show whether you’re on track.

Days You Can Miss works out how many absences you have left before dropping below your target. This is useful if your school or course requires a minimum attendance percentage.

Homeschool Tracker tracks completed school days against your planned or required total and shows how much of the year you have left.

How to Calculate Attendance Percentage

The attendance percentage formula is:

Attendance percentage = (days attended ÷ total days held) × 100

For example, if 60 school days have taken place and you’ve attended 57:

57 ÷ 60 × 100 = 95% attendance

You can use exactly the same formula for a school year, individual class, college course, week, or month. The important part is to divide the number attended by the number that have actually taken place.

How to Calculate Absence Percentage

To work out the percentage you’ve missed instead:

Absence percentage = (days missed ÷ total days held) × 100

If you’ve missed 3 out of 60 days:

3 ÷ 60 × 100 = 5% absence

Your attendance and absence percentages should add up to 100%.

Attendance Percentage Chart

For a typical 180-day school year, here’s how common attendance percentages translate into days:

Attendance	Days Attended	Days Missed
100%	180	0
95%	171	9
90%	162	18
85%	153	27
80%	144	36
75%	135	45
70%	126	54

So 95% attendance means 9 days missed in a 180-day year, while 90% attendance means 18 days missed.

The numbers will be different if your school year or course has a different total. Enter your own figures in the calculator rather than relying on the 180-day examples.

What Happens to Your Attendance When You Miss a Day?

How much your attendance drops depends on how many days or classes have already taken place.

For example:

• Attend 19 out of 20 days = 95%
• Attend 49 out of 50 days = 98%
• Attend 99 out of 100 days = 99%
• Attend 179 out of 180 days = 99.4%

An absence therefore has a much bigger effect near the beginning of a school year or course.

The same applies if you’ve missed several days. If you’ve attended 95 out of 100 school days, your attendance is 95%. Miss another five days without attending any additional days and it becomes 90.5% (95 out of 105).

Use your actual totals in the calculator above to see exactly where you stand.

How Many Days Can You Miss and Still Have 90% Attendance?

In a 180-day school year, 90% attendance requires at least 162 days attended. That means a maximum of 18 missed days.

But that’s only the final-year calculation. If you’re partway through the year, the number of absences you have left depends on how many you’ve already used.

That’s what the Days You Can Miss calculator above works out. Enter the full number of school days or classes, your attendance so far, and the percentage you need to maintain.

Don’t treat this as permission to miss a particular number of days. Schools, colleges, districts, and states can have separate absence policies even when your overall percentage remains above the target.

Using the Calculator for Homeschool Attendance

Homeschool attendance requirements vary by state. Some states specify instructional days, others use instructional hours, and requirements may differ by age or grade.

If your state requires a certain number of school days, use the Homeschool Tracker to compare the days you’ve completed with your required or planned total.

If your state measures instruction in hours, keep your official records in hours rather than assuming they can be converted directly into school days.

You can check your state’s requirements with the homeschool laws by state tool.

More Student Calculators and Tools

Use the school days calculator to count school days between dates, excluding weekends.

The homeschool planner printable includes space for attendance and other school records, while the GPA calculator calculates weighted and unweighted GPA for high school students.

You can also browse all of our interactive student tools.

Last Updated on 26 August 2026 by Clare Brown