The short answer
Start from your size, not from the print. Many of our two-person mommy and me dresses stop at XL, while the family matching sets in our plus-size range reach 2XL, 3XL or 4XL. Those sets can be bought as just two pieces, for you and your child, so they are the place to begin if you wear above an XL.
| Your question | The straight answer |
|---|---|
| How high do the sizes go? | 4XL, which the size chart lists as US 22W with a 48.4 to 50.8 in chest and 50.8 to 53.1 in hips. Not every style goes that far. |
| Do I have to buy for the whole family? | No. Each size is one piece. Several sets also have a separate mommy and me listing that shows only the women's and children's sizes. |
| How far do the children's sizes go? | Usually to a girls' 8-9Y, and to 12-13Y on some sets. Many include baby sizes, and many include a boy's top. |
| Which letter do I order? | Measure bust, waist and hips, then read the inches. Our women's letters run about one letter smaller than a typical US adult chart. |
| What if my size is gone in that print? | Match on color instead. A solid in a color from your child's print still reads as a pair in a photo. |
Where should you start looking?
Start in our plus size women's clothes collection, then work outward. Our mommy and me dresses and mommy and me outfits have more of the two-person looks, but on the size menus we read, most of them ended at XL.
The table shows how far different kinds of matching set went when we read their size menus in November 2026. Treat it as a guide to what to expect, since styles come and go.
| Style | Largest women's letter listed | Child's half |
|---|---|---|
| Belted knit dress with front buttons and cap sleeves | 4XL | Girl to 12-13Y, baby, and a boy's top on the family listing |
| Cami dress with a solid top and printed skirt | 4XL | Girl to 12-13Y, baby, boy's top |
| Smocked-bodice dress with short sleeves and a tiered skirt | 4XL | Girl to 8-9Y, baby, boy's top |
| Tank-top dress with a printed skirt | 4XL | Girl to 8-9Y, baby, boy's top |
| V-neck strap dress with a hidden snap | 3XL | Girl to 12-13Y, baby, boy's top |
| Crossover V-neck dress with flutter sleeves | 2XL | Girl and baby |
| Smocked cotton strap dresses and strap jumpsuits | XL | Girl to 8-9Y or 11-12Y, baby |
A letter on the menu does not mean it is in stock. Family sets sell down one size at a time, and on some pages we read, one or two of the larger sizes were available while their neighbors were gone. Check your size and your child's size together, and put both in one basket.
How do you measure, and which letter do you order?
Take three measurements and let the inches pick the letter. The PatPat size chart asks for these, with a soft tape held snug but not tight:
- Bust: around the fullest part, arms relaxed, with the tape parallel to the floor.
- Waist: around your natural waistline, the smallest area.
- Hips: feet together, around the fullest part.
| Letter | US | Chest (in) | Waist (in) | Hips (in) |
|---|---|---|---|---|
| XL (standard chart) | 16-18 | 40.5 to 43 | 33.5 to 36 | 42.5 to 45 |
| 2XL (plus chart) | 18W | 43.7 to 46.1 | 36.6 to 39 | 46.1 to 48.4 |
| 3XL (plus chart) | 20W | 46.1 to 48.4 | 39 to 41.3 | 48.4 to 50.8 |
| 4XL (plus chart) | 22W | 48.4 to 50.8 | 41.3 to 43.7 | 50.8 to 53.1 |
Four things can mislead you here:
- Your usual letter. As does PatPat run small explains, our women's letters are drafted for a chest about 1.5 to 2 inches smaller than the same letter on a typical US adult chart. If you wear XL elsewhere, start by checking 2XL here.
- The letters that skip. The chart also lists 0XL and 1XL, but no women's size menu we checked offers either. The menus go straight from XL to 2XL. If your numbers fall in those rows, compare them with XL and 2XL above.
- XXL and 2XL. The standard chart has an XXL row (US 20) and the plus chart has a 2XL row (18W), but the menus show only 2XL, and the listings do not say which row that 2XL is cut to. The two rows are close, with chests of 43.5 to 46 in and 43.7 to 46.1 in, so if you are near the top of either, take the next size up. The same goes for 3XL and the standard XXXL.
- The US number. A size label is one brand's own claim, and the National Institute of Standards and Technology no longer works on apparel-size standards. Trust the inches over any number on the tag.
If your numbers fall above the 4XL row, this range will not fit you. For scale, the ASTM body tables for plus sizes run from 14W to 40W, so our chart covers only part of that span. The section on matching by color below is written with that in mind.
For your child, go by height rather than age. The numbers are on the same size chart.
Does the larger size fit the same way as the smaller ones?
Not exactly, and two details are worth checking. We have not measured the finished garments, so this comes from the charts and from how each dress is built.
The plus chart has its own proportions. PatPat's charts treat it as a fuller cut, not a scaled-up version of the standard letters. It also drafts for more height as the sizes rise, from 66.9 to 68.9 inches at 2XL to 68.9 to 70.9 inches at 3XL and 4XL. If you are shorter than your band, expect a waist seam to sit lower and a hem to fall longer than the photo suggests.
The photo may show a smaller size. Some family sets include a photo on a plus-size model and another on a smaller model, usually near the front of the gallery. Look for the one closest to your size, and compare where the waist and hem land.
A few construction details decide how much room for adjustment you have:
| Detail | What it can do | What it cannot do |
|---|---|---|
| Adjustable straps | Raise the waist and hem together | Add room at the bust |
| Tie belt | Let you set the waist where you like it, or leave it loose | Change the length of the bodice |
| Smocked bodice | Stretch across a range of bust sizes | Stretch beyond where it is sewn, such as a sleeve, or give lift |
| Front buttons | Open the neckline a little | Hide strain at the bust or hips if the size is too small |
Your half and your child's half may not be the same design, either. Sleeves, straps and length can differ between the two versions, so check the child's photo as well as your own. For one dress on its own, including fabric, sheerness, bras and chafing, see plus-size dresses for women.
Can you match a son as well as a daughter?
Yes, and the family sets make it easy. Many of the dresses in our plus-size range come with a coordinating boy's tee, polo or shirt that uses the same print on a panel or pocket, or a solid color from it.
Use the family listing rather than the mommy and me listing when you are shopping for a boy, since some two-person listings show only girls' and baby sizes. On the product page, choose under the Family Member option: Women for your dress, then Boy for his top. Nobody else needs to be in the order.
With a daughter, how closely you match should change as she gets older. Mother and daughter matching outfits goes through it age by age, including the point where she outgrows the child's half. If your baby is still being carried, mommy and baby matching outfits explains how contrast keeps them visible against you.
What if your size is not in the print you love?
Match on color, and buy your half wherever fits you best. This also works if your measurements are above our chart, or if you simply prefer another brand's clothes.
- Buy your child's half first. Choose the print they like.
- Pull one color from it. Look for a color that shows up clearly and that you already wear.
- Wear that color as a solid. A dress, or a top and skirt, from anywhere. You will have more choice in cut and support this way than you would in any single set.
- Check them together in daylight. Two shades that match indoors can drift apart outside.
In a photo, a print and a solid in the same color read as deliberate. They also leave you with a garment you can wear with anything else. The three-color method shows how to carry this across a whole family.
What should you test before the day itself?
Try the outfit doing what you will actually do in it. Mommy and me outfits get lifted, leaned on and sat on the floor in, and that is where sizing problems tend to show.
- Lift your child. See whether the straps slide or the neckline shifts with a child on your hip.
- Sit down on the floor and stand up. Tiered and smocked dresses usually give you room. Check that you can get up without stepping on the hem.
- Raise your arms. On a short-sleeved dress, make sure the sleeve does not pull at the upper arm. Smocking at the bodice will not help with that.
- Stay in it for ten minutes. Rubbing at a bra band or strap shows up with time, not in the mirror.
Try everything on before you wash it, because retailers generally do not accept washed returns.
How do you get a good photo of the two of you?
Treat it like any other mommy and me photo. You do not need special poses or a dark color, and nothing in this article is about looking smaller. What helps is the same for everyone: soft light, a plain background, and enough contrast that two people stay two people.
- Watch the print on the smaller person. The same print repeats many times on a long dress but may show only one or two motifs on a small child. Prints with smaller motifs hold together better across both sizes.
- Use open shade. Soft light beats midday sun for everybody in the frame.
- Do something together. Reading, walking or lifting your child usually looks more natural than standing still.
Frequently asked questions
Do plus size mommy and me sets cost more than smaller sizes? Sometimes, because on some listings the largest sizes are priced higher. Check the price with your size selected rather than the price on the collection page.
Is a PatPat 3XL the same as a 3X from another brand? Not necessarily, because each brand sets its own sizes. Compare your measurements with our 3XL row, which is a 46.1 to 48.4 in chest and 48.4 to 50.8 in hips.
My bust and hips point to different letters. Which one matters? Follow the part of the dress with the least room, which is usually the bust on a dress with a full skirt. Take the larger letter if you are close on a style with no stretch.
Are there plus-size matching pajamas and swimsuits too? Yes, the plus-size collection also holds family pajamas and swimsuits, and their size menus vary. Most of the pajamas we read stopped at 3XL.
Can I match with a child who is not a girl or a baby? Yes. Many family listings include a boy's top, and you can order it with only your dress.
What if my child is older than the sizes in the set? Use the shared-color approach, with each of you in your own garment. A child past the top of the set can still choose a piece in a color from your print.
About this article
Written and fact-checked by the PatPat Editorial Team. How we research, source and review what we publish is set out on our editorial standards page.
Method. Size figures and measuring instructions come from the PatPat size chart. Size menus and availability were read from live product data in the three collections linked above in November 2026, and they change often. We did not wear-test or measure these outfits, so the fit notes are reasoning from the charts and each garment's construction.
Sources. Size figures: PatPat size chart. Letter comparison and returns: Does PatPat run small. Plus-size body tables: ASTM D6960/D6960M. Sizing standards: NIST.
Last updated 5 November 2026 · Next review November 2027
