What an IXL SmartScore actually means
Last updated Aug 31, 2026
The short answer
A SmartScore is IXL's 0-100 measure of how well a student understands one skill. It is not the percentage of questions they answered correctly. IXL's own thresholds are:
| SmartScore | What IXL calls it |
|---|---|
| 100 | Mastery |
| 90 | Excellence, the entry point to IXL's Challenge Zone |
| 80 | Proficiency |
So a student sitting at 80 has met IXL's bar for proficiency on that skill, and a student at 100 has mastered it. Everything below 80 is work in progress, not a failing grade.
Why it is not a percentage
In a percentage grade, a missed question is a permanent deduction. IXL describes the SmartScore as "completely different": a student who starts badly and then answers well can still reach 100 in the same session.
The score also drives the questions. IXL states that when a student answers correctly and the SmartScore rises, the following questions get harder; when they answer incorrectly the score falls and the following questions get easier. That is why two students with the same SmartScore have usually seen different questions, and why the score is a reading of current understanding rather than a record of the session.
What a SmartScore does not tell you
It does not place a student against their grade level. A SmartScore measures one skill and moves within a single practice session. IXL's LevelUp Diagnostic is the product that places a student above, on, below or far below grade level, and it reports on a different scale entirely. Averaging or trending the two together compares two different measurements.
It does not carry over between skills. Each IXL skill has its own SmartScore. A student with 100 on "Add fractions with like denominators" has said nothing yet about unlike denominators.
A score can be stale. IXL recalculates a skill's SmartScore as a student returns to it, so a number from three months ago describes three months ago.
How to read a SmartScore as a teacher
- 100 is the only number that means mastery. Treat 80-99 as real progress that is not finished.
- A drop between two sessions on the same skill is worth more attention than a low first score. The first score is a starting point; a fall is a change.
- Time matters as much as the number. A 70 reached in six minutes and a 70 reached in forty minutes are different situations for the same child.
- A benchmark session is not practice. If your school runs the LevelUp Diagnostic in benchmark mode, that time shows up alongside practice and will flatten a practice average if it is folded in.
Frequently asked questions
Is a SmartScore of 80 good?
Yes. 80 is IXL's own published threshold for proficiency in a skill. It is not mastery, which IXL reserves for 100.
What does a SmartScore of 100 mean?
IXL says a student who has earned 100 on a skill has mastered that topic.
Is a SmartScore the percentage of questions answered correctly?
No. IXL contrasts the SmartScore with percentage scoring specifically: a missed question is not a permanent deduction, and a student can recover within the same session.
Why did the SmartScore go down?
An incorrect answer lowers the SmartScore, and IXL then serves easier questions until the student is answering correctly again.
Can a SmartScore be compared across two different skills?
Only loosely. Each skill is scored on its own, so 90 on one skill and 90 on another mean "close to excellence on this skill" twice, not one combined level.
Sources
- IXL, The IXL SmartScore: the key to mastery-based learning
- IXL, LevelUp vs Flex Diagnostic comparison
Lorsey is not affiliated with or endorsed by IXL Learning. IXL and SmartScore are trademarks of their respective owner, used here to describe the product a school already has.