Correction (October 8, 2026): Original annual files change the starting twelfth-grade count, several ratios and derived grade-band totals. This article now describes enrollment rather than graduates. Unsupported explanations, district-universe claims, quotations and forecasts have been removed.

Colorado reported 57,438 kindergartners and 74,923 twelfth graders in 2025–2026, last school year's membership and the most recent published data. The difference was 17,485 students. These are enrolled grade counts: twelfth-grade membership is not a count of graduates, and kindergarten membership is not a count of all students entering public schools.

At the starting endpoint, 2014–2015, the state reported 66,068 kindergartners and 63,001 twelfth graders. Kindergarten membership subsequently fell by 8,630 students, or 13.1%, while twelfth-grade membership increased by 11,922, or 18.9%.

The comparisons use the original annual files linked through the Colorado Department of Education's membership collection. Individual historical totals are not replaced by later landing-page revisions.

A descriptive ratio

The ratio was 104.9 kindergartners per hundred enrolled twelfth graders at the starting endpoint and 76.7 at the final endpoint. The decline was 28.2 ratio points, calculated before rounding the endpoints.

Kindergarten membership first fell below twelfth-grade membership in 2015–2016 and remained below it in every subsequent year of the checked history. The final ratio was the lowest in that window.

In 2020–2021, kindergarten membership fell by 5,800 students, or 9.1%. The ratio moved from 91.1 in the preceding year to 81.4, then rebounded to 86.5 in 2021–2022. That rebound did not restore parity.

A ratio below parity describes different sizes of two grades in the same annual snapshot. It does not establish future system growth or contraction, because these files do not follow the same students through moves, transfers, repetition or graduation.

Lower and higher grades differed

Between the endpoints, every grade from kindergarten through eighth had a lower count, while every grade from ninth through twelfth had a higher count.

First grade lost 10,377 students, or 15.1%, the largest absolute loss among those grades. Eighth grade lost 441 students, or 0.7%. The differences therefore varied substantially across grades.

The complete sum of published ninth-through-twelfth-grade counts peaked at 282,903 students in 2023–2024 within the checked window. It then fell by 567 students and by another 4,756 in the next two annual comparisons, reaching 277,580 in 2025–2026. All four grade counts were available for those calculations; no missing grade was treated as zero.

Selected district comparisons

Jefferson County R-1^↗ET reported 4,934 kindergartners last school year, down from 6,134 at the starting endpoint, a loss of 1,200 students.

Denver County 1^↗ET reported 6,480 kindergartners and 6,500 twelfth graders in 2025–2026. At the starting endpoint, its counts were 7,560 and 4,514 respectively. The comparison moved from more kindergartners to slightly more enrolled twelfth graders; it is not a comparison with diploma recipients.

Pueblo City 60^↗ET reported 916 kindergartners, down from 1,503, a decline of 39.1%. These named comparisons do not establish how many organizations statewide met a particular grade-ratio condition.

The annual records demonstrate changed grade sizes. They do not determine how much births, migration or schooling choices contributed, or how large any future graduating class will be.

Detailed code that reproduces the analysis and figures in this article is available exclusively to EdTribune subscribers.