Dimension reference Baby crib

Furniture · Reference

Standard Crib Dimensions: Interior, Mattress & Slat-Gap Chart

A US full-size crib has a mandated interior of 28 × 52 3/8 in (71 × 133 cm), measured between innermost surfaces, and fits a mattress at least 27 1/4 × 51 5/8 in. EU cots use 60 × 120 cm.

Length (interior)Side heightWidth (interior)

US full-size crib interior is measured between the innermost surfaces at the mattress-support level; mattress must fit snugly with no oversized gaps.

Key facts

  • A US full-size crib has a legally mandated interior of 28 ± 5/8 in (71 cm) wide × 52 3/8 ± 5/8 in (133 cm) long, measured between innermost surfaces (16 CFR 1219).
  • The crib mattress must be at least 27 1/4 × 51 5/8 in (690 × 1310 mm) and no more than 6 in (~152 mm) thick so the rails stay a safe height.
  • Crib slats, spindles and rods may be no more than 2 3/8 in (6 cm) apart at any point (ASTM F1169), the classic "soda-can" rule.
  • A "non-full-size" crib is one whose interior length is over 55 in (139.7 cm) or under 49 3/4 in (126.3 cm), or width over 30 5/8 in (77.7 cm) or under 25 3/8 in (64.3 cm) — governed by 16 CFR 1220.
  • European cots (EN 716) are sized by mattress: 60 × 120 cm is the standard cot and 70 × 140 cm the convertible cot-bed.

US full-size crib — mandated interior dimensions (16 CFR 1219)

Interior dimensionMetricImperialMeasured between
Width71 ± 1.6 cm28 ± 5/8 inInnermost surfaces of the crib sides
Length133 ± 1.6 cm52 3/8 ± 5/8 inInnermost surfaces of the crib end panels

Source: eCFR / LII — 16 CFR § 1219.1 (Full-Size Baby Cribs) (2011)

Required full-size crib mattress (16 CFR 1241)

RequirementImperialMetric
Minimum mattress width27 1/4 in690 mm
Minimum mattress length51 5/8 in1310 mm
Maximum corner gap (fit test)3.15 in80 mm

Source: eCFR / LII — 16 CFR § 1241.2 (Crib Mattresses) (2022)

EU / UK cot & cot-bed — BS EN 716

SpecMetricImperial
Standard cot mattress60 × 120 cm≈ 24 × 47 in
Cot-bed (convertible) mattress70 × 140 cm≈ 27.5 × 55 in
Max gap between cot bars/slats60 mm≈ 2 3/8 in
Max mattress-to-frame gap30 mm≈ 1 3/16 in

Source: BS EN 716-1 baby cot safety standard (Picket&Rail) (2017)

Put these numbers on the product photo

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FAQ

What are the interior dimensions of a standard crib?

A US full-size crib interior is 28 ± 5/8 in (71 ± 1.6 cm) wide and 52 3/8 ± 5/8 in (133 ± 1.6 cm) long, measured between the innermost surfaces of the sides and end panels (16 CFR 1219).

What size mattress fits a standard crib?

A full-size crib mattress must be at least 27 1/4 × 51 5/8 in (690 × 1310 mm) and no more than 6 in (~152 mm) thick, fitting snugly with no more than a two-finger gap at the sides.

How far apart can crib slats be?

No more than 2 3/8 in (6 cm) between any adjacent slats, spindles or rods (ASTM F1169) — roughly the width of a soda can — to prevent head or limb entrapment.

What's the difference between a full-size and non-full-size crib?

Full-size cribs meet the 28 × 52 3/8 in interior spec (16 CFR 1219). Non-full-size cribs (16 CFR 1220) fall outside it: length over 55 in or under 49 3/4 in, or width over 30 5/8 in or under 25 3/8 in.

What size is a European cot or cot-bed mattress?

Under EN 716 the standard cot mattress is 60 × 120 cm (~24 × 47 in) and the larger convertible cot-bed is 70 × 140 cm (~27.5 × 55 in), with a mattress-to-frame gap of no more than 30 mm.

Sources & method

Every figure on this page is traced to a named source, linked under each table. Standard sizes come from published standards and established industry references; where a size is a typical range or varies by manufacturer, we say so. Sizes vary by region, model and revision — treat these as the standard reference, and confirm the exact spec of the item you are selling.

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Standard Crib Dimensions (2026): Interior & Mattress Size