U.S. TIMSS Science Scores 2023: Grade 4 and Grade 8
TIMSS 2023 placed U.S. science achievement above the grade-specific international average at both assessed grades. Grade 4 and Grade 8 results come from separate national samples and separate grade-level scales, so the score difference between grades is not a student-growth measure.
U.S. Science Score Snapshot
National average scores and their distance from the TIMSS 2023 international average.
U.S. Scores Compared With the TIMSS 2023 International Average
Grade-specific science averages for the United States and participating non-benchmarking education systems.
The international average is recalculated for each grade and cycle. It is different from the fixed TIMSS scale centerpoint of 500.
Grade 4 and Grade 8 Science Results
The comparison counts classify other participating education systems as scoring higher than, not measurably different from, or lower than the U.S. average.
| Grade | U.S. score | Intl. avg. | U.S. minus intl. | Higher-scoring systems | Similar systems | Lower-scoring systems | 10th pct. | 90th pct. | P90–P10 gap |
|---|---|---|---|---|---|---|---|---|---|
| Grade 4 | 532 | 494 | +38 | 11 | 12 | 39 | 404 | 645 | 241 |
| Grade 8 | 513 | 478 | +35 | 11 | 6 | 27 | 385 | 634 | 249 |
Science Achievement Over Time
U.S. average science scores and score-distribution endpoints from each available TIMSS administration since 1995.
U.S. TIMSS Science Score Trend
National average scale scores by assessment year.
NCES reports no measurable change from 2019 to 2023 in the average science score at either grade. Grade 4 was not administered in 1999.
| Grade | Year | Average | 10th pct. | 90th pct. |
|---|---|---|---|---|
| Grade 4 | 1995 | 542 | 419 | 654 |
| Grade 4 | 2003 | 536 | 426 | 636 |
| Grade 4 | 2007 | 539 | 427 | 643 |
| Grade 4 | 2011 | 544 | 440 | 641 |
| Grade 4 | 2015 | 546 | 439 | 644 |
| Grade 4 | 2019 | 539 | 426 | 641 |
| Grade 4 | 2023 | 532 | 404 | 645 |
| Grade 8 | 1995 | 513 | 384 | 628 |
| Grade 8 | 1999 | 515 | 386 | 636 |
| Grade 8 | 2003 | 527 | 419 | 628 |
| Grade 8 | 2007 | 520 | 410 | 623 |
| Grade 8 | 2011 | 525 | 416 | 625 |
| Grade 8 | 2015 | 530 | 421 | 631 |
| Grade 8 | 2019 | 522 | 388 | 642 |
| Grade 8 | 2023 | 513 | 385 | 634 |
TIMSS International Benchmarks in Science
Percentages are cumulative: each value is the share of U.S. students scoring at or above the stated benchmark.
| Grade | Advanced ≥625 | High ≥550 | Intermediate ≥475 | Low ≥400 |
|---|---|---|---|---|
| Grade 4 | 15% | 46% | 75% | 91% |
| Grade 8 | 12% | 37% | 66% | 87% |
Distribution Changes Since 2019
Average-score stability does not mean every part of the score distribution moved in the same way.
Lower-score movement is more visible in Grade 4
- At Grade 4, the 10th-percentile score was 22 points lower in 2023 than in 2019, while the 90th-percentile score was not measurably different. NCES reports the 2023 P90–P10 gap of 241 points was larger than in every prior administration except 1995.
- The Grade 4 share reaching at least the Low benchmark was 91% in 2023, compared with 94% in 2019. NCES reports the 2023 share was lower than in every administration from 2003 through 2019.
- At Grade 8, the P90–P10 gap was 249 points in 2023 and 254 points in 2019; NCES does not identify those two gaps as measurably different.
Data Sources and Measurement
NCES TIMSS 2023 U.S. Results
NCES TIMSS 2023 Technical Notes
IEA TIMSS 2023 Results
2023
0–1,000 science scale; fixed centerpoint 500 and standard deviation 100
63 education systems at Grade 4; 45 at Grade 8
TIMSS is administered every four years and reports Grade 4 and Grade 8 science on grade-specific scales that are maintained over time. The 500 centerpoint is fixed for scale interpretation, while the international average is recalculated from participating non-benchmarking education systems for each grade and cycle, with each system weighted equally in that international mean.
The international benchmarks are Advanced at 625, High at 550, Intermediate at 475, and Low at 400. Benchmark percentages are cumulative shares at or above each threshold. Percentile estimates describe the national score distribution; the P90–P10 gap is the difference between the 90th- and 10th-percentile scores.
U.S. Grade 4 met the international participation standard after replacement schools were included. The Grade 8 sample did not meet the overall participation standard; its school participation rate was at least 50% before replacement, and the U.S. result remains included in international reporting with the applicable annotation. This sampling note should be retained when interpreting cross-system comparisons.
Published values are rounded. NCES tests differences with unrounded estimates and their sampling errors, so a visible point difference alone does not establish a measurable change. The Grade 4 and Grade 8 results represent different cohorts and grade-level assessments and should not be used as a within-student growth comparison.