Pupils per class, primary: Fewer pupils per class in primary school, after pay, no target

Current law. No general legal cap. Cap of 24 pupils in grande section (final year of nursery school), CP and CE1, and halving of these classes in REP/REP+ since 2017. Average in public elementary schools: 21.3 pupils per class in 2024; the minister announces 21.0 for the first time at the start of the 2025 school year. Primary level (public and private): 6.15 million pupils today, fewer than 5.7 million forecast in 2029 (DEPP, cited by the Senate).

Horizon. full year 2032, €bn/year, compared with current policies

Limits. Calculation: posts = P/(s×(s−1)), with P ≈ 4.95m public-sector pupils in 2029-2032 (editors' assumption: 87% of 5.7m) and s = 21, i.e. about 11,800 posts. Cost per post at the centre: €48,336 excluding the CAS Pensions (State pensions special account), brought back to pay for active service (48,336 / 1.145 ≈ €42,200), i.e. €0.5bn; high value: about €70k per post counting the contribution to the CAS Pensions. “Net” convention (R9), the same as for the public sector pay index point and public sector headcount: at the centre, cost excluding all employer contributions paid to other public administrations (CAS Pensions, employer social contributions); as upper bound, full employer cost. The published “excluding CAS” cost still includes employer contributions other than the CAS: it is brought back to pay for active service alone by the ratio “average loaded cost excluding CAS / pay for active service” from the PAP 2024 (Enseignement scolaire, entry-exit costs: 47,634 / 41,610 = 1.145 in primary, 51,198 / 44,265 = 1.157 in secondary, about 1.15 on average; editors' calculation). The cost is not linear: each pupil fewer costs more than the previous one (going from 21 to 18 costs more than three times the unit). Decisive point: current policies cut posts in line with demographics (4,018 in 2026). A candidate who “maintains posts” therefore reduces class sizes at no cost compared with 2026, but at a cost compared with the reference trajectory. The DEPP note on class sizes and the RERS (education.gouv.fr) were not accessible: the figures come from the Senate, not from the DEPP. Option moyenne-19 (average of 19): same method, same sources and same assumptions as the parameter (4.95m public-sector pupils in 2029-2032). Posts = P/19 − P/21 = 4.95m × (1/19 − 1/21) ≈ 24,800, at about €42,200 (€48,336 excluding the CAS Pensions, brought back to pay for active service), i.e. €1.05bn; €1.74bn at about €70k per post with the contribution to the CAS Pensions. Caution: the lever is defined as a maximum number of pupils per class, whereas the cost schedule costs an average. A cap at a given level costs considerably more than an average at the same level. A position is therefore costed only if the text targets an average.

• Sénat, rapport spécial PLF 2026, Enseignement scolaire (O. Paccaud), 2025-11: « Le nombre d'élèves du premier degré s'établirait à moins de 5,7 millions en 2029, contre actuellement 6,15 millions d'élèves. »
• Sénat, avis commission culture PLF 2026, Enseignement scolaire, 2025-11-25: « le nombre moyen d'élèves par classe dans l'élémentaire s'élève en 2024 à 21,3, en baisse de 9,7 % par rapport à 2014 ; [ministre] c'est la moyenne 21,0 par classe qui sera atteinte pour la première fois cette année. »
• AN, amendement II-CF1985 PLF 2026 (rapporteur spécial A. Boulogne), 2025-11-03: « coût moyen chargé hors CAS pensions global, qui est de 48 336 euros pour les enseignants du premier degré (Projet annuel de performances pour 2026, p.52) ; 1 891 ETP → 91,40 millions d'euros »