3BRE · Leading the Build™ · Phase 1 — Planning, Budgeting & Programming

Enrollment Calculator

Long-range enrollment scenarios, grade by grade. Set your opening year and target class sizes, enter the enrollment ladder, and the tool derives classrooms needed, capacity, and average class size — the numbers your budget and facility program are built on.

Selected project—

Step 1School & timeline

These frame the projection. Change the horizon and the grids below re-shape automatically.

first year of operation
2–10 columns
to
e.g., 9th to 12th for a high school
Enrollment at capacity
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Entry-grade sections
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Opening-year enrollment
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Enrollment at capacity
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Classrooms at capacity
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Avg class size at capacity
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Read-only access. You can view and export this calculator, but changes will not be saved.

Step 2Enrollment by grade & year

Enter planned enrollment for each grade in each year, and a target class size per grade. Grades with 0 students are simply not yet served. Only the grades-served range from Step 1 is shown.

Ladder mode:

Legend:white bordered cells are yours to fill inshaded cells are calculated for you

Step 3Classrooms needed (core + specials)

Core classrooms per grade = enrollment ÷ target class size, rounded up. Add specials / flex rooms per grade in the gold column (e.g., +1 science room each for 6th–8th) — they count only in years that grade has students, and roll into Total classrooms. Room-by-room programming (labs, art, music, gym) lives in the Programming tool — this is the classroom envelope it starts from.

How the math works. Classrooms per grade-year = ceiling(enrollment ÷ target class size); average class size = enrollment ÷ classrooms. Capacity figures read from the final projection year. A planning model, not a promise — authorizer enrollment caps and year-one realities govern. · Leading the Build™ · 3BRE LLC
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