Brand Comparison · 2026

    UniqlovsOld Navy, Size Comparison

    Uniqlo tends to run smaller than Old Navy. If you wear a Medium at Old Navy, you may need a Large at Uniqlo. For a measurement-based recommendation, use the fit checker.

    Quick Answer

    Uniqlo vs Old Navy sizing, quick answer

    Uniqlo runs about one size smaller than Old Navy. If you wear a Medium at Old Navy, you'll likely need a Large at Uniqlo. For an exact recommendation, build a free fit profile.

    • Uniqlo: fits true to size
    • Old Navy: runs large
    • If between sizes: size up at the brand that runs smaller, or use the fit checker below for a personalised recommendation.

    Brand guide

    Compare how Uniqlo and Old Navy usually fit, where cuts feel slimmer or roomier, and which categories are most predictable.

    GENERAL BRAND GUIDANCE

    This is a general brand-level sizing summary, not an exact product recommendation. For your specific size, paste a product link into the fit checker.

    The Verdict

    Uniqlo sizing compared to Old Navy: Uniqlo fits true to size while Old Navy runs large. Here is how the sizes translate.

    Uniqlo tends to run smaller than Old Navy. If you wear a Medium at Old Navy, you may need a Large at Uniqlo. For a measurement-based recommendation, use the fit checker.

    UniqloTRUE TO SIZE
    Old NavyRUNS LARGE
    Uniqlo logo

    Uniqlo

    TRUE TO SIZE

    Boxy Japanese cuts, true to size for a relaxed fit

    Old Navy logo

    Old Navy

    RUNS LARGE

    Generous American sizing, runs large

    Category Match-up

    Uniqlo
    Old Navy
    Tops
    TRUE TO SIZE

    Boxy, Japanese-inspired cuts. True to size for a relaxed fit.

    RUNS LARGE

    Generous, relaxed cuts. Runs large. Size down for a fitted look.

    Bottoms
    TRUE TO SIZE

    True to size. Selvedge denim is rigid, size up if between sizes.

    RUNS LARGE

    Jeans run large with a roomy seat. Rockstar jeans are the exception, those run slim.

    Outerwear
    TRUE TO SIZE

    Ultra Light Down runs true to size.

    No data for Old Navy Outerwear

    Activewear

    No data for Uniqlo Activewear

    RUNS LARGE

    PowerSoft and Go-Dry leggings run large. Size down for compression.

    Size Conversion Table

    Your SizeUniqloOld Navy
    XXSXXS<XXS(Runs Large)
    XSXSXXS(Runs Large)
    SSXS(Runs Large)
    MMS(Runs Large)
    LLM(Runs Large)
    XLXLL(Runs Large)
    XXLXXLXL(Runs Large)
    XXXLXXXLXXL(Runs Large)

    * Indicative only. For your personalised size at both brands,

    Common Questions

    Does Uniqlo run smaller than Old Navy?

    Uniqlo runs about one size smaller than Old Navy. If you wear a Medium at Old Navy, you'll likely need a Large at Uniqlo. For an exact recommendation, build a free fit profile.

    Should I size up or down at Uniqlo vs Old Navy?

    Size up one at Uniqlo compared to Old Navy. Uniqlo runs smaller, so if you wear a Medium at Old Navy, try a Large at Uniqlo, especially for fitted tops and tailored bottoms.

    If I'm a Medium at Uniqlo, what size am I at Old Navy?

    Since Uniqlo runs smaller than Old Navy, a Medium at Uniqlo is roughly equivalent to a Small at Old Navy. Use the ThisFits fit checker for a recommendation based on your measurements.

    Does Uniqlo or Old Navy fit differently by category?

    Yes, fit varies meaningfully by category. Tops, Bottoms can each fit differently than the brand's overall tendency suggests. See the Category Match-up section below for per-category guidance.

    Which brand is more accurate to its size chart, Uniqlo or Old Navy?

    Uniqlo and Old Navy both publish official size charts, but real-world fit varies by fabric, cut and category. The ThisFits engine cross-references published charts with shopper fit reports across 197+ brands to predict your size in each.

    What if I'm between sizes at Uniqlo and Old Navy?

    If you're between sizes, Uniqlo tends to fit closer to the body, so trying the larger size first usually means fewer returns. Always confirm each retailer's return policy before ordering.

    More Comparisons

    Your Personal Size

    See your size in Uniqlo&Old Navy

    Build your fit profile once and see your likely size for Uniqlo and Old Navy, based on your measurements.

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    Your size in both brands