R129 size checker: which seat types fit a child’s stature?
Enter a stature to see which R129 seat types the regulation allows, the rear-facing rule that applies and the Q-dummy band used in testing.
Based on UN R129 04 series (Suppl. 4) limits in §6.1.2.7, §6.1.2.8, §6.1.3.3 and §6.1.3.6. A seat is only suitable within the stature range printed on its own approval label.
How the checker works
The checker applies the stature and age limits written into UN R129 04 series:
- Under 15 months, only rearward- or lateral-facing seats may be used (§6.1.2.7).
- Forward-facing integral seats cannot be designed for statures below 76 cm (§6.1.2.7).
- Infant carriers go up to 87 cm at most (§6.1.2.8).
- High-back boosters start at 100 cm and must protect against side impact up to 135 cm (§6.1.3.3).
- Booster cushions start at 125 cm (§6.1.3.6).
Choosing an actual seat
The regulation sets the outer limits; every seat is approved for its own range. Always read the size range on the seat’s approval label and the maximum occupant mass for harnessed seats, and check the vehicle handbook for i-Size or ISOFIX positions. Learn to read an R129 label.
Frequently asked
Why does R129 use height instead of weight?
Stature is easier for parents to measure and better predicts how a child fits the seat’s shell, harness and belt geometry. R129 checks internal dimensions such as shoulder height and sitting height against anthropometric data for every stature in the declared range.
My child is over 15 months but under 76 cm. Can they face forward?
No. Forward-facing integral seats may not be designed for statures below 76 cm, so a forward-facing R129 seat will not be approved for that child. Rear-facing is allowed at any age.
Can a 110 cm child use a booster cushion?
Not an R129 booster cushion: cushions may not be approved or declared for use below 125 cm. A high-back booster seat (from 100 cm) is the R129 option.