Head Start and Early Head Start ratios and class sizes for grantees

Head Start sets preschool class composition as a cap on the number of children, paired with the teaching staff who must be in the room.

A class that serves a majority of children who are 3 years old may have no more than 17 children, with a teacher and a teaching assistant or two teachers.

A class where the majority are 4- and 5-year-olds may have no more than 20.

The age of the majority decides which cap applies.

A room of 4-year-olds with one 3-year-old in it is still a majority-4 class; the cap only changes when enrollment shifts the balance and a different age group becomes the majority.

Track the class list against the caps as enrollment moves, not just at the start of the year.

For orientation, Caring for Our Children — the best-practice standard from the American Academy of Pediatrics and the American Public Health Association — recommends 7:1 with a maximum group of 14 for 3-year-olds, and 8:1 with a maximum group of 16 for 4- and 5-year-olds.

CFOC is a recommendation, not law, and not the rule a grantee is measured against; the 1302.21 caps above are.

One caveat before you build a staffing plan on those numbers: they are the current rule as of October 2026, and ACF published a proposal on August 7, 2026 to rescind and replace the Head Start Program Performance Standards, with comments due October 6, 2026.

It is a proposal, not a final rule — the caps above still govern — but confirm the current text with the Office of Head Start before you commit to a multi-year classroom plan.

Practically, the cap is the number that drives your staffing budget: every class sits inside it with the required teaching staff in the room — the rule allows only two narrow flexes, covered under double-session staffing below.

The qualification floors for the teachers and assistants who fill those rooms are part of the same rulebook — our Head Start staffing rules guide covers qualifications, background checks, training and pay.

Early Head Start classrooms serve children under 36 months, and the numbers are tighter than preschool's.

A class must have two teachers with no more than eight children, or three teachers with no more than nine.

On top of the class caps, each teacher is primarily responsible for no more than four children.

Caring for Our Children's best-practice rows for this age band are 3:1 with a maximum group of 6 for children 12 months and younger, and 4:1 with a maximum group of 8 for children 13 to 35 months.

Those are recommendations, not law — the 1302.21 numbers above are the ones a grantee is held to.

For scheduling, the per-teacher limit matters as much as the class cap: a nine-child room runs on three teachers only while responsibility stays at or below four children per teacher, and the caps and the per-teacher limit travel together — a classroom cannot hold nine children with only two teachers on the schedule.

Build substitute coverage into the schedule rather than counting on stretching a room.

Head Start's numbers do not override your state's.

The same 1302.21 rule says that where state licensing is stricter, the program must meet the stricter rule.

The two rulebooks stack: a Head Start classroom has to satisfy the federal caps and — where your state's licensing rule is stricter — your state licensing agency's ratios too, and the tighter number is the one that decides how many children the room can take.

A looser state rule does not loosen the federal caps — the 1302.21 limits apply to a grantee's classrooms either way.

Federal CCDF rules do not set numeric ratios; each state describes its own group size limits and child-to-caregiver ratios by age in its CCDF Plan, under 45 CFR 98.41(d).

The numbers that bind a specific classroom therefore come from that state's current rule — not from a national table, and not from another state's.

Check the stricter number before you schedule. Pull your state's current ratios from your state child care licensing agency, set them beside the 1302.21 caps for each age band, and plan each room to whichever is tighter.

This page is not your state's rule text — confirm both rulebooks with the agencies that administer them before you set an enrollment cap or finalize a staffing schedule.

Who counts toward ratio while a room is running — floaters, the director stepping in, aides, substitutes — is its own set of questions: see who counts in ratio for the general rules centers staff to.

A double-session class serves two separate groups of children in the same day, each group attending a part-day session rather than one group attending for a full day.

The class caps drop in that model: a class with a majority of 3-year-olds is limited to 15 children in double session instead of 17, and a class where the majority are 4- and 5-year-olds is limited to 17 instead of 20.

The lower per-session cap is what lets the model carry more children across the day: the same room turns over between two groups, so daily enrollment can run higher than a single class would allow while each session stays inside a tighter ceiling.

The staffing pressure point is the turnover in the middle — sessions switch, and the teaching team has to hold the cap on both sides of the changeover.

The caps are hard ceilings for scheduled staffing, but the rule allows two narrow flexes during the day.

A brief teacher absence of up to five minutes is explicitly allowed.

During nap time, one teaching staff member may be replaced by one staff member or trained volunteer who does not meet the teaching qualifications required for the age.

Both flexes are narrow — a five-minute gap and a sleeping room — and neither covers a vacancy on the schedule.

This page is employer information, not licensing or legal advice. Class-size and staffing rules come from the Office of Head Start's Program Performance Standards and from your state child care licensing agency — confirm the current numbers with both before you set enrollment caps or build a staffing schedule.