Staff Calculator math
How the calculator turns student counts into staffing FTE
The results page does not use one blanket ratio. It starts with enrollment, selects the right population for each role, applies the configured formula, then rounds only where the position must be staffed in whole people.
Students
Grade enrollment plus support counts
Settings
Ratios, thresholds, service minutes, group sizes
Formula
Role-specific FTE calculation
Required FTE
Rounded only when the position requires whole FTE
Normal enrollment
Grade or full-building counts
Teachers and many support roles use the full grade band selected in the ratio settings.
Special groups
EL, ASD, CI, Tier 3, SLP
Specialized roles use the matching support count instead of total enrollment.
Output
Required FTE
Filled FTE is compared later; it does not change the required staffing calculation.
Calculation flow
The same five steps run for each position
The important detail is step two: the target student base changes by role. A classroom teacher may use one grade, an SLP may use caseload workload, and an EL teacher may use service-band minutes.
Load enrollment and supports
Choose the student base
Apply the position formula
Round by position rules
Compare with filled FTE
Core formulas
How normal FTE is calculated
Most positions are ratios, fixed allocations, or building-level threshold models. Ratio settings can be scoped to all students, one grade band, or a special population.
| Model | Plain English | Formula | Controlled By |
|---|---|---|---|
| Grade teachers | Each grade is counted separately so one crowded grade cannot hide another grade's need. | ceil(grade enrollment / (students per teacher x tolerance) x teachers) | Grade-level teacher ratios and teacher overage tolerance. |
| Standard ratio positions | The calculator turns the selected student count into FTE using the configured staff-to-student ratio. | (target students x staff ratio) / student ratio | Staff, students, grade band, special population source. |
| Fixed amount | The position receives the configured FTE regardless of enrollment. | staff ratio or base FTE | Calculation method = fixed_amount. |
| Per building | The building receives the same base allocation when the position is building-level. | base FTE or staff ratio | Allocation type = per_building. |
| Floor-based | A building gets a minimum FTE, then additional FTE as enrollment crosses each threshold block. | base FTE + floor((target students - threshold) / threshold) x increment | Floor method, threshold students, base FTE, increment staff. |
| Threshold-based | A building gets 0 below the threshold, then the base allocation at the threshold and increments after that. | 0 if target < threshold; otherwise base FTE + floor((target - threshold) / threshold) x increment | Threshold method, threshold students, base FTE, increment staff. |
Special populations
How SE, EL, MTSS, SLP, and K-1 groups are counted
Special groups do not inflate general enrollment. The calculator reads the support counts saved for the selected building or district scope, then uses the role-specific formula below.
| Group | Count Used | Formula | Rounding |
|---|---|---|---|
| EL / ELL teacher | EL students split into 300-minute and 150-minute weekly service bands. If service bands are blank, total EL students fall into the 150-minute band. | weekly demand minutes / weekly capacity minutes, where demand = (300-band x 300) + (150-band x 150) and capacity = floor(daily minutes / session length) x session length x group size x 5 | Partial FTE is allowed. |
| Bilingual paraprofessional | Total EL students from the 300-minute and 150-minute service bands. | (total EL students x staff ratio) / student ratio | Partial FTE is allowed. |
| Reading interventionist | Tier 3 reading students below the 20th percentile, distributed across K-5, 6-8, and 9-12 in proportion to enrollment. | ceil(band Tier 3 count / (floor(daily available minutes / session minutes) x reading group size)) for each grade band | Each band rounds up, then the bands are added. |
| Math interventionist | Tier 3 math students below the 20th percentile, distributed across K-5, 6-8, and 9-12 in proportion to enrollment. | ceil(band Tier 3 count / (floor(daily available minutes / session minutes) x math group size)) for each grade band | Each band rounds up, then the bands are added. |
| ASD special education teacher | ASD students. | ceil((ASD students / students per ASD classroom) x staff ratio) | Whole FTE. |
| MOCI/MICI special education teacher | CI students. | ceil((CI students / students per MOCI/MICI classroom) x teacher ratio) | Whole FTE. |
| Special education paraprofessional | ASD students and CI students. | ASD aide classrooms if ASD students >= 3, plus ceil((CI students / CI classroom size) x teacher ratio) | Whole classroom support counts. |
| Speech-language pathologist | SLP caseload students and SLP evaluation workload. | (caseload students + evaluation students x evaluation weight) / maximum caseload | Partial FTE is allowed unless the position definition is configured otherwise. |
| General paraprofessional | Kindergarten and 1st grade enrollment only. | ((K students + 1st grade students) x staff ratio) / student ratio | Partial FTE is allowed unless configured otherwise. |
Worked examples
What the formulas mean in plain English
These examples use simple numbers to show the shape of the math. Your actual results depend on the ratios and intervention parameters saved in your scenario.
Grade teacher
62 fourth graders, 28 students per teacher, 5% overage tolerance.
ceil(62 / (28 x 1.05)) = 3 teachers
The tolerance lets a class slightly exceed the base ratio before another FTE is added, but the final count is still a whole teacher.
EL teacher
8 students need 300 minutes per week and 30 students need 150 minutes.
(8 x 300 + 30 x 150) / (8 sessions x 30 minutes x 6 students x 5 days) = 0.96 FTE
EL staffing is driven by service minutes, not just a headcount, when service-band settings are available.
MTSS reading
Tier 3 reading students are split across K-5, 6-8, and 9-12 based on each band's enrollment share.
ceil(band Tier 3 / daily intervention capacity) for each band
Each band rounds up independently so a small secondary need is not hidden inside an elementary total.
Results view
Required FTE, filled FTE, and gap are separate.
Required FTE
calculated from enrollment, supports, ratios, and parameters
Gap FTE
required FTE - filled FTE
Fill rate
filled FTE / required FTE