Gap Kids is frequently described as the premium sibling of Old Navy — same parent company, similar sizing, higher price. The first part is accurate. The second part is not, and the difference matters when you're trying to decide whether the same size works across both brands.
When we put the verified measurements side by side, Gap Kids and Old Navy have different waist targets and meaningfully different hip targets at the same height. Gap's hip measurements run notably wider relative to waist — a different body proportion assumption that produces a different fit even at equivalent size labels. A child who fits neatly in Old Navy XS(5) may find Gap Kids XS(5) roomy through the seat.
Gap Kids also uses two parallel label systems that cover similar height ranges with completely different amounts of information — and knowing which label to use changes whether you have any body measurement data at all for your purchase.
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Enter your child's measurements and we'll show the right size — plus how long it will last.
Size recommendations are based on official brand size charts and are provided as a guide only. Fit may vary by item, style, and individual child. Outgrow is not responsible for sizing decisions made based on these recommendations.
The Two Label Systems — Which One to Use
Gap Kids sells kids clothing under two parallel systems that cover nearly identical height ranges but with completely different amounts of published measurement data.
| System | Example labels | Height coverage | Body measurements |
|---|---|---|---|
| Age labels | 4 yrs, 5 yrs | 99–114cm | Height + weight only. No waist or hip. |
| Alpha labels | XS(4), XS(5), S(6), S(7) | 99–132cm | Height, waist and hip published. |
The age label garments are the toddler-adjacent sizes — cut with extra room for children transitioning out of toddler sizing. They cover similar height ranges to the alpha label XS but with different proportions and no body measurement data published. For bottoms especially, buying by the alpha label is always the better approach because you have actual waist and hip data to match against your child's measurements.
Gap Kids vs Old Navy — Not the Same Sizing
Both brands are owned by Gap Inc. and parents consistently assume the sizing is identical. At the waist it is close — Gap XS(5) targets 56cm versus Old Navy's 57.2cm, a 1.2cm difference. Through the hip the difference is much more significant.
| Brand | Size at 107–114cm | Waist | Hip |
|---|---|---|---|
| Gap Kids | XS (5) | 56cm | 65cm |
| Old Navy | XS (5) | 57.2cm | 61.6cm |
Gap's hip target is 3.4cm wider than Old Navy's at the same height. That difference is enough to produce a noticeably different fit through the seat and thighs. Gap is cut wider through the hips relative to waist — a different body proportion assumption. For a child who fits neatly through the waist in both brands, Gap will feel roomier through the bottom half.
One Child, Six Brands — How Gap Kids Compares
The same child from our comparison series: 112cm, 19.5kg, 53.5cm waist, 58.5cm hip. Gap Kids XS(5) gives a waist match but with 6.5cm of hip room to spare — the loosest hip fit of all the brands that return a match.
| Brand | Size | Waist target | Wear time | Note |
|---|---|---|---|---|
| H&M | No match | 110: 56–58cm | 116: 58–59cm | — | Child falls between 2cm brackets. |
| Cat & Jack | No match | 52.7cm | — | Child exceeds ceiling by 0.8cm. |
| Carter's | 5 | 55.5–58.5cm | ~3 months | Fits. Weight approaching limit. |
| Gap Kids | XS (5) | 56cm waist / 65cm hip | ~4 months | Fits. Hip 6.5cm below target — generous through seat. Limited by height. |
| Old Navy | XS (5) | 57.2cm | ~5 months | Fits. Child 3.7cm below target. Limited by height. |
| Zara | 116 | 55cm | ~8 months | Best result. Child 1.5cm below target. Limited by height. |
Child profile: 112cm / 44in, 19.5kg / 43lbs, 53.5cm waist, 58.5cm hip. Wear time based on Outgrow longevity data.
For the full methodology see our cross-brand sizing research. See also our complete kids clothing size chart comparing 36+ brands side by side.
Gap Kids Boys Tops Size Chart
Boys and girls tops share identical measurements throughout. Age labels (4 yrs, 5 yrs) publish height and weight only. Alpha labels (XS, S, M) publish chest measurements. The S(6-7) bracket spans 16cm — one of the widest single-label brackets of any brand in our database.
| Label | Height (cm) | Chest (cm) | Weight (kg) |
|---|---|---|---|
| Up to 7 lbs | 0–46 | — | 0–3 |
| 0-3 mos | 46–58 | — | 3–5 |
| 3-6 mos | 58–68 | — | 5–8 |
| 6-9 mos | 68–71 | — | 8–9 |
| 6-12 mos | 71–74 | — | 9–10 |
| 12-18 mos | 74–79 | — | 10–12 |
| 18-24 mos | 79–84 | — | 12–14 |
| 2 yrs | 84–91 | — | 13–15 |
| 3 yrs | 91–99 | — | 15–17 |
| 4 yrs | 99–106 | — | 17–18 |
| XS (4-5) | 99–114 | 58–61 | 15–22 |
| 5 yrs | 106–114 | — | 18–21 |
| S (6-7) | 114–130 | 64–66 | 21–28 |
| M (8-9) | 130–137 | 69 | 28–33 |
| L (10-11) | 137–145 | 71 | 33–38 |
| XL (12-13) | 145–152 | 74 | 39–44 |
| XXL (14-16) | 152–170 | 76 | 44–54 |
Note: S(6-7) covers 114–130cm — a 16cm bracket. Age labels (4 yrs, 5 yrs) publish no chest data.
Boys & Girls Tops — Husky
| Label | Height (cm) | Chest (cm) | Weight (kg) |
|---|---|---|---|
| S (6-7) Husky | 114–130 | 68–71 | 22–31 |
| M (8-9) Husky | 130–137 | 73 | 31–37 |
| L (10-11) Husky | 137–145 | 76 | 37–43 |
| XL (12-13) Husky | 145–152 | 79 | 43–48 |
| XXL (14-16) Husky | 152–170 | 81–83 | 48–61 |
Gap Kids Boys Bottoms Size Chart
Boys and girls bottoms share identical measurements for Standard and Slim. Age labels publish no waist or hip data — always use the alpha label for bottoms.
| Label | Height (cm) | Waist (cm) | Hip (cm) | Weight (kg) |
|---|---|---|---|---|
| Up to 7 lbs | 0–46 | — | — | 0–3 |
| 0-3 mos | 46–58 | — | — | 3–5 |
| 3-6 mos | 58–68 | — | — | 5–8 |
| 6-9 mos | 68–71 | — | — | 8–9 |
| 6-12 mos | 71–74 | — | — | 9–10 |
| 12-18 mos | 74–79 | — | — | 10–12 |
| 18-24 mos | 79–84 | — | — | 12–14 |
| 2 yrs | 84–91 | — | — | 13–15 |
| 3 yrs | 91–99 | — | — | 15–17 |
| 4 yrs | 99–106 | — | — | 17–18 |
| XS (4) | 99–107 | 53 | 61 | 15–17 |
| 5 yrs | 106–114 | — | — | 18–21 |
| XS (5) | 107–114 | 56 | 65 | 18–20 |
| S (6) | 114–124 | 57 | 67 | 20–25 |
| S (7) | 124–132 | 58 | 70 | 25–29 |
| M (8) | 132–137 | 60 | 72 | 29–32 |
| L (10) | 137–145 | 61 | 76 | 32–37 |
| XL (12) | 145–152 | 64 | 80 | 37–42 |
| XXL (14) | 152–157 | 66 | 84 | 42–48 |
| XXL (16) | 157–163 | 69 | 89 | 48–52 |
| XXXL (18) | 163–168 | 71 | 94 | 52–57 |
Age labels (4 yrs, 5 yrs) have no waist or hip data. XS covers 99–114cm across two sub-sizes with a 3cm waist difference between them.
Boys & Girls Bottoms — Slim
| Label | Height (cm) | Waist (cm) | Hip (cm) | Weight (kg) |
|---|---|---|---|---|
| XS (4) Slim | 99–107 | 48 | 55 | 14–16 |
| XS (5) Slim | 107–114 | 50 | 59 | 16–19 |
| S (6) Slim | 114–124 | 52 | 62 | 19–22 |
| S (7) Slim | 124–132 | 53 | 64 | 22–26 |
| M (8) Slim | 132–137 | 54 | 67 | 26–30 |
| L (10) Slim | 137–145 | 56 | 71 | 30–34 |
| XL (12) Slim | 145–152 | 59 | 74 | 34–39 |
| XXL (14) Slim | 152–157 | 60 | 78 | 39–44 |
| XXL (16) Slim | 157–162 | 63 | 83 | 44–49 |
| XXXL (18) Slim | 163–168 | 66 | 88 | 49–54 |
Boys & Girls Bottoms — Plus
Plus starts at M(8) — 132cm and above. No Plus option for XS or S sizes.
| Label | Height (cm) | Waist (cm) | Hip (cm) | Weight (kg) |
|---|---|---|---|---|
| M (8) Plus | 132–137 | 68 | 80 | 33–37 |
| L (10) Plus | 137–145 | 70 | 83 | 37–41 |
| XL (12) Plus | 145–152 | 73 | 87 | 42–47 |
| XXL (14) Plus | 152–157 | 74 | 91 | 47–48 |
| XXL (16) Plus | 157–163 | 77 | 96 | 53–58 |
| XXXL (18) Plus | 163–168 | 77 | 101 | 59–63 |
Gap Kids Girls Bottoms Size Chart
Girls bottoms share identical measurements with boys for Standard, Slim and Plus. Same charts apply.
Gap Kids Shoe Size Chart
Gap Kids shoes use US sizing as the primary label with EU and UK equivalents. Boys and girls share the same chart. Measure foot length heel to longest toe while standing.
| Label | EU | US | UK | Foot length (cm) |
|---|---|---|---|---|
| US 1 | 16 | 1 | 0 | 9.2 |
| US 2 | 17 | 2 | 1 | 10.0 |
| US 3 | 18 | 3 | 2 | 10.9 |
| US 4 | 19 | 4 | 3 | 11.7 |
| US 5 | 22 | 5 | 4 | 12.5 |
| US 6 | 23 | 6 | 5 | 13.4 |
| US 7 | 24 | 7 | 6 | 14.2 |
| US 8 | 25 | 8 | 7 | 15.0 |
| US 9 | 26 | 9 | 8 | 15.9 |
| US 10 | 27 | 10 | 9 | 16.7 |
| US 11 | 28 | 11 | 10 | 17.5 |
| US 12 | 29 | 12 | 11 | 18.4 |
| US 13 | 30 | 13 | 12 | 19.3 |
| US 1Y | 31 | 1Y | 13 | 20.1 |
| US 2Y | 32 | 2Y | 1 | 21.0 |
| US 3Y | 33 | 3Y | 2 | 21.8 |
| US 4Y | 34 | 4Y | 3 | 22.7 |
| US 5Y | 35 | 5Y | 4 | 23.5 |
| US 6Y | 36 | 6Y | 5 | 24.3 |
Frequently Asked Questions
Does Gap Kids run big or true to size?
Gap Kids sits close to average for waist measurements but runs notably generous in the hip. At the same height Gap Kids targets a significantly wider hip than Old Navy or Carter’s — garments that fit well in the waist can feel roomy through the seat. Use your child’s height to find the right size and expect a relaxed fit through the hips.
Is Gap Kids the same sizing as Old Navy?
No — despite both being owned by Gap Inc., the measurements differ meaningfully. At 107–114cm height, Gap Kids XS(5) targets a 56cm waist and 65cm hip. Old Navy XS(5) targets a 57.2cm waist and 61.6cm hip. Gap has a 3.4cm more generous hip at the same height. Check measurements before assuming the same size works in both brands.
What is the difference between Gap Kids age labels and alpha labels?
Gap Kids uses two parallel label systems at similar height ranges. The numeric age labels (4 yrs, 5 yrs) publish only height and weight — no waist or hip data. The alpha labels (XS, S, M, L) publish waist and hip measurements. For bottoms, always use the alpha label system so you have body measurement data to match against your child.
What does Gap Kids XS mean?
Gap Kids XS covers 99–114cm with two distinct sub-sizes — XS(4) from 99–107cm with a 53cm waist, and XS(5) from 107–114cm with a 56cm waist. A 3cm waist difference exists between the two sub-sizes within the same XS label. Check which sub-size applies to your child’s height before buying.
Does Gap Kids have extended sizing?
Yes — Gap Kids offers Slim and Plus fits. Slim is available from XS(4) onward. Plus starts at M(8), covering 132cm and above. There is no Plus option for XS or S sizes, meaning broader children at 99–132cm have no Gap Kids Plus alternative in bottoms.
How does Gap Kids compare to Carter’s?
Gap Kids and Carter’s are similar in waist at equivalent heights but Gap runs more generous in the hip. Carter’s doesn’t publish hip measurements at all, while Gap does — meaning Gap gives parents more complete information for fitting bottoms. Both brands sit in the middle of the cross-brand waist range at the kids size.