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    How to measure May 20, 2026 4 min read

    How to Measure a Child for a Costume

    Halloween costumes go over warm layers. Always size up 1. Here's the measurement set + the layering rule.

    Measure Over Layers

    1. Wear the layer system the costume will go over (Halloween: t-shirt + sweater).
    2. Height barefoot against wall.
    3. Chest, waist, hip over the layers.
    4. Sleeve over base + mid layer.
    5. Size up 1 from chart-suggested size for Halloween.

    Costume Size by Age + Height

    AgeHeightCostume sizeChest
    2T33-36"2T21-22"
    4T39-42"4T / 4-523-24"
    644-47"5-6 / S25-26"
    848-51"7-8 / M27-28"
    1052-55"9-10 / L29-30"
    1256-59"11-12 / XL31-32"
    1460-63"13-1433-34"

    Common Mistakes

    Sizing without layers in mind

    Halloween in cold weather = costume over sweater. Size up 1.

    Buying months before the event

    Kids grow. Buy 4-6 weeks before the event for best fit.

    Long hems that drag

    Costume hem must clear the floor for safe trick-or-treating.

    Tight costumes for active kids

    Kids run, climb, and play in costumes. Never size down.

    FAQs

    How are costumes sized?

    Kids' XS-XL or 2T-14, by height + chest.

    Size up for Halloween?

    Yes — 1 size up for warm-layer wearing.

    Costume vs regular kids' clothing?

    Costumes are looser, less structured.

    Between sizes?

    Always size up.

    Play vs Halloween costumes?

    Play: true to size. Halloween: 1 up.

    How long can same size last?

    1-2 Halloweens.

    One Number, One Size Up, Done

    For full kids' chart see kids' clothing size chart.

    Selling kids' costumes on Shopify?

    Tailor Size Guide adds height + layered chest matching to every costume listing.