Awesome! Fit great. Love it
The Onyx Romper | Zip Up
Step into the zip up Onyx romper - our best seller!
Size :
S
Smith D.
Verified
Love the color vibrancy, fun, great material, receives so many compliments. I’m 6’ 3”, 205 lbs, and I went with a Large. Fits great!
Vinz L.
Verified
It’s my first rompers and i love it. I thought it wont look good on me but all my friends loved it when they saw me wearing :)
Michael M.
Verified
They are a great color and fit really well! Love them!!
All-Occasion Ready
Smart Details
Tailored Slim Fit
Butter-Soft Fabric
The Onyx Romper: Your New Go-To Style
Butter Soft Cotton Poly Blend Material | Zip Up Romper
Comfort Meets Style
The Onyx Romper is designed with the modern man in mind, combining comfort and style effortlessly. Made from soft, breathable fabric, this romper feels great against the skin, making it perfect for all-day wear. Whether you're out running errands or lounging at home, the onyx romper provides the comfort you need without sacrificing your fashion sense.
Versatile Fashion Choice
What sets the onyx romper apart is its versatility. It features a zip-up front that not only adds a trendy touch but also allows for easy wear and removal. You can dress it up with a smart jacket for a night out or keep it casual with sneakers for a day in the park. Because of its adaptable style, this romper is suitable for various occasions, making it a staple in any wardrobe.
Easy Care and Maintenance
Caring for your onyx romper is simple and convenient. The fabric is machine washable, ensuring that you can maintain its quality and vibrant color without a hassle. So, you can keep your favorite outfit fresh and ready for any adventure that comes your way. Investing in this romper means you're choosing practicality and style together, a decision that will pay off in your everyday life.
Size & Fit Guide
Find your fit. Own your look. Our rompers and jumpsuits are designed for a modern, tailored silhouette—and the right size makes all the difference.
Use this guide to learn how each style fits, take your measurements, compare our size charts, and get a personalized recommendation with WAIR.
How RomperJack Fits
SHORTS / ONE PIECE
Rompers
RomperJack rompers have a slim, fitted silhouette through the chest, waist, and shorts. They're designed to look sharp rather than loose or oversized.
If you're between sizes, have broader shoulders or thighs, or simply prefer a little extra room, consider the larger size.
PANTS / ONE PIECE
Jumpsuits
Our jumpsuits feature a European-inspired slim fit, with a streamlined upper body and tapered leg. They're cut for a tailored, modern look.
Because they're full-length, pay particular attention to the torso and rise. You should be able to sit, reach, and bend comfortably without pulling through the shoulders or crotch.
Between sizes? The larger size is generally a better starting point for comfort and movement, especially if you have a longer torso or prefer a less fitted look. Fabric and fit may vary by style; always check the product details.
How to Measure Your Body
Use a flexible tape measure over lightweight clothing or against your skin. Keep it level and comfortably snug, not tight. Having someone help can improve accuracy.
01 / CHEST
Chest
Wrap the tape under your arms and around the fullest part of your chest.
02 / WAIST
Waist
Measure around your natural waist, generally above your belly button. Don't hold your stomach in.
03 / HIPS
Hips & Seat
Measure around the fullest part of your hips and seat so you have room to sit and move.
04 / HEIGHT
Height
Stand straight without shoes and measure from the floor to the top of your head.
05 / INSEAM
Inseam
Measure from the crotch along the inside of your leg to your desired pant hem. Especially useful for jumpsuits.
06 / TORSO
Torso Length
Check how much length you need between your shoulder and crotch. Longer torsos often need extra room in a one-piece style.
Compare chest and waist measurements with the charts below. Height, weight, and length provide extra context; they should not replace a comfortable fit through your torso.
ROMPERJACK ORIGINALS
Romper Size Chart
Designed with a slim, fitted cut. Compare your chest and waist first, then use the height and weight ranges as additional guidance.
Romper Sizing
Best used for RomperJack-branded rompers only. All body measurements are shown in inches; weight is shown in pounds.
| Size | Chest | Waist | Height | Weight (lbs) |
|---|---|---|---|---|
| S | 34–38" | 26–28" | 64–68" | 140–155 |
| M | 38–40" | 28–30" | 65–70" | 155–170 |
| L | 40–42" | 30–32" | 65–73" | 170–190 |
| XL | 42–44" | 32–34" | 68–74" | 190–210 |
| XXL | 44–46" | 34–36" | 74–77" | 190–210 |
| XXXL | 46–48" | 36–38" | 70–77" | 210+ |
Fit noteThis chart is intended as a guide. If you're between sizes or prefer more room, size up.
Best forUse chest and waist as your starting point, then use height and weight as secondary guidance.
Romper Fit Example
See the fit in action
Our rompers are designed for a close, tailored fit through the chest and waist, with room to move comfortably through the shorts. Use the model photo to see how the silhouette sits on the body.
Size reference: At 6'0" and 190 lbs, Large can be a useful starting point, depending on your chest, waist, and torso measurements. Individual fit may vary.
ROMPERJACK ORIGINALS
Jumpsuit Size Chart
Our jumpsuits are slim-fitting with a tapered cut. Consider chest, waist, and overall torso comfort when selecting your size.
Jumpsuit Sizing
Best used for RomperJack-branded jumpsuits only. Measurements are shown in inches.
| Size | Chest | Waist | Length |
|---|---|---|---|
| S | 35–37" | 26–28" | 28" |
| M | 37–39" | 28–30" | 30" |
| L | 39–42" | 30–33" | 31" |
| XL | 42–44" | 33–35" | 33" |
| XXL | 44–46" | 35–38" | 34" |
| XXXL | 46–50" | 38–40" | 44" |
Fit noteJumpsuits are designed for a slimmer, European-inspired fit with a tapered leg.
Best forUse chest and waist first, then confirm the overall length and torso comfort based on your body proportions.
Jumpsuit Fit Example
6'0" · 190 lbs · Size Large
The model is 6 feet tall, weighs 190 lbs, and wears a Large. This shows how our slim, tapered jumpsuit is designed to sit through the shoulders, waist, and legs.
For your best fit, compare your chest and waist measurements, and consider your torso length before selecting a size.
PERSONALIZED SIZE RECOMMENDATIONS
Need a Second Opinion? Try WAIR.
Not sure which size to choose? The interactive WAIR sizing tool can help you find a recommended size for participating RomperJack rompers and jumpsuits, based on information about your body and fit preferences.
Open the romper or jumpsuit you're shopping for, look for the WAIR sizing option near the size selector, and follow the prompts. WAIR is accessed on participating product pages—not directly from this guide.
WAIR is a helpful recommendation tool. Review the product description and fit details before making your selection.
PLEASE NOTE
About RJ Picks & Partner Sizing
This size guide applies only to RomperJack-branded rompers and jumpsuits.
Styles in RJ Picks are curated from partner brands and may follow different size standards. For shirts, pants, shorts, jackets, shoes, accessories, two-piece sets, and other partner products, refer to the individual product page or the partner brand's website for accurate sizing information.
Do not assume that the RomperJack charts or WAIR recommendations apply to RJ Picks products.
Size & Fit FAQs
Do RomperJack rompers and jumpsuits run small?
They're designed with a slim, tailored silhouette, not a relaxed or oversized fit. If you're between sizes or prefer extra room, consider sizing up.
What's most important when sizing a one-piece?
Chest and waist are your starting points, but torso length and the room you need to sit or bend comfortably are also important.
Can I use these charts for RJ Picks items?
No. RJ Picks partner products may use different sizing. Use the size information on that product's page or on the partner brand's website.
Currently, store credit is only available for returns and exchanges. Once your return or exchange has been processed, you will receive an email containing a RomperJack E-Gift card code for the amount of the item returned, not including any initial shipping charges. Please submit a return here. Read our return policy here.
We offer standard 3- to 7-business-day shipping and 2- to 5-business-day priority shipping for Domestic orders. Some items may be on preorder, which is stated on the product page. This may take longer to ship. International shipping can take anywhere between 7 and 21 business days.
If you order a preorder item and an in stock item, your full order will ship only when the preorder inventory is available at our warehouse. If you need the in stock item before the preorder, please make a separate purchase. For preorder shipping dates, please check the product description section. Some gift cards and promotions may not be available for preorders.
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Regular price
$ 79.00
Shipping calculated at checkout.
Size :
S
The Onyx Romper: Your New Go-To Style
Butter Soft Cotton Poly Blend Material | Zip Up Romper
Comfort Meets Style
The Onyx Romper is designed with the modern man in mind, combining comfort and style effortlessly. Made from soft, breathable fabric, this romper feels great against the skin, making it perfect for all-day wear. Whether you're out running errands or lounging at home, the onyx romper provides the comfort you need without sacrificing your fashion sense.
Versatile Fashion Choice
What sets the onyx romper apart is its versatility. It features a zip-up front that not only adds a trendy touch but also allows for easy wear and removal. You can dress it up with a smart jacket for a night out or keep it casual with sneakers for a day in the park. Because of its adaptable style, this romper is suitable for various occasions, making it a staple in any wardrobe.
Easy Care and Maintenance
Caring for your onyx romper is simple and convenient. The fabric is machine washable, ensuring that you can maintain its quality and vibrant color without a hassle. So, you can keep your favorite outfit fresh and ready for any adventure that comes your way. Investing in this romper means you're choosing practicality and style together, a decision that will pay off in your everyday life.
Size & Fit Guide
Find your fit. Own your look. Our rompers and jumpsuits are designed for a modern, tailored silhouette—and the right size makes all the difference.
Use this guide to learn how each style fits, take your measurements, compare our size charts, and get a personalized recommendation with WAIR.
How RomperJack Fits
SHORTS / ONE PIECE
Rompers
RomperJack rompers have a slim, fitted silhouette through the chest, waist, and shorts. They're designed to look sharp rather than loose or oversized.
If you're between sizes, have broader shoulders or thighs, or simply prefer a little extra room, consider the larger size.
PANTS / ONE PIECE
Jumpsuits
Our jumpsuits feature a European-inspired slim fit, with a streamlined upper body and tapered leg. They're cut for a tailored, modern look.
Because they're full-length, pay particular attention to the torso and rise. You should be able to sit, reach, and bend comfortably without pulling through the shoulders or crotch.
Between sizes? The larger size is generally a better starting point for comfort and movement, especially if you have a longer torso or prefer a less fitted look. Fabric and fit may vary by style; always check the product details.
How to Measure Your Body
Use a flexible tape measure over lightweight clothing or against your skin. Keep it level and comfortably snug, not tight. Having someone help can improve accuracy.
01 / CHEST
Chest
Wrap the tape under your arms and around the fullest part of your chest.
02 / WAIST
Waist
Measure around your natural waist, generally above your belly button. Don't hold your stomach in.
03 / HIPS
Hips & Seat
Measure around the fullest part of your hips and seat so you have room to sit and move.
04 / HEIGHT
Height
Stand straight without shoes and measure from the floor to the top of your head.
05 / INSEAM
Inseam
Measure from the crotch along the inside of your leg to your desired pant hem. Especially useful for jumpsuits.
06 / TORSO
Torso Length
Check how much length you need between your shoulder and crotch. Longer torsos often need extra room in a one-piece style.
Compare chest and waist measurements with the charts below. Height, weight, and length provide extra context; they should not replace a comfortable fit through your torso.
ROMPERJACK ORIGINALS
Romper Size Chart
Designed with a slim, fitted cut. Compare your chest and waist first, then use the height and weight ranges as additional guidance.
Romper Sizing
Best used for RomperJack-branded rompers only. All body measurements are shown in inches; weight is shown in pounds.
| Size | Chest | Waist | Height | Weight (lbs) |
|---|---|---|---|---|
| S | 34–38" | 26–28" | 64–68" | 140–155 |
| M | 38–40" | 28–30" | 65–70" | 155–170 |
| L | 40–42" | 30–32" | 65–73" | 170–190 |
| XL | 42–44" | 32–34" | 68–74" | 190–210 |
| XXL | 44–46" | 34–36" | 74–77" | 190–210 |
| XXXL | 46–48" | 36–38" | 70–77" | 210+ |
Fit noteThis chart is intended as a guide. If you're between sizes or prefer more room, size up.
Best forUse chest and waist as your starting point, then use height and weight as secondary guidance.
Romper Fit Example
See the fit in action
Our rompers are designed for a close, tailored fit through the chest and waist, with room to move comfortably through the shorts. Use the model photo to see how the silhouette sits on the body.
Size reference: At 6'0" and 190 lbs, Large can be a useful starting point, depending on your chest, waist, and torso measurements. Individual fit may vary.
ROMPERJACK ORIGINALS
Jumpsuit Size Chart
Our jumpsuits are slim-fitting with a tapered cut. Consider chest, waist, and overall torso comfort when selecting your size.
Jumpsuit Sizing
Best used for RomperJack-branded jumpsuits only. Measurements are shown in inches.
| Size | Chest | Waist | Length |
|---|---|---|---|
| S | 35–37" | 26–28" | 28" |
| M | 37–39" | 28–30" | 30" |
| L | 39–42" | 30–33" | 31" |
| XL | 42–44" | 33–35" | 33" |
| XXL | 44–46" | 35–38" | 34" |
| XXXL | 46–50" | 38–40" | 44" |
Fit noteJumpsuits are designed for a slimmer, European-inspired fit with a tapered leg.
Best forUse chest and waist first, then confirm the overall length and torso comfort based on your body proportions.
Jumpsuit Fit Example
6'0" · 190 lbs · Size Large
The model is 6 feet tall, weighs 190 lbs, and wears a Large. This shows how our slim, tapered jumpsuit is designed to sit through the shoulders, waist, and legs.
For your best fit, compare your chest and waist measurements, and consider your torso length before selecting a size.
PERSONALIZED SIZE RECOMMENDATIONS
Need a Second Opinion? Try WAIR.
Not sure which size to choose? The interactive WAIR sizing tool can help you find a recommended size for participating RomperJack rompers and jumpsuits, based on information about your body and fit preferences.
Open the romper or jumpsuit you're shopping for, look for the WAIR sizing option near the size selector, and follow the prompts. WAIR is accessed on participating product pages—not directly from this guide.
WAIR is a helpful recommendation tool. Review the product description and fit details before making your selection.
PLEASE NOTE
About RJ Picks & Partner Sizing
This size guide applies only to RomperJack-branded rompers and jumpsuits.
Styles in RJ Picks are curated from partner brands and may follow different size standards. For shirts, pants, shorts, jackets, shoes, accessories, two-piece sets, and other partner products, refer to the individual product page or the partner brand's website for accurate sizing information.
Do not assume that the RomperJack charts or WAIR recommendations apply to RJ Picks products.
Size & Fit FAQs
Do RomperJack rompers and jumpsuits run small?
They're designed with a slim, tailored silhouette, not a relaxed or oversized fit. If you're between sizes or prefer extra room, consider sizing up.
What's most important when sizing a one-piece?
Chest and waist are your starting points, but torso length and the room you need to sit or bend comfortably are also important.
Can I use these charts for RJ Picks items?
No. RJ Picks partner products may use different sizing. Use the size information on that product's page or on the partner brand's website.
Currently, store credit is only available for returns and exchanges. Once your return or exchange has been processed, you will receive an email containing a RomperJack E-Gift card code for the amount of the item returned, not including any initial shipping charges. Please submit a return here. Read our return policy here.
We offer standard 3- to 7-business-day shipping and 2- to 5-business-day priority shipping for Domestic orders. Some items may be on preorder, which is stated on the product page. This may take longer to ship. International shipping can take anywhere between 7 and 21 business days.
If you order a preorder item and an in stock item, your full order will ship only when the preorder inventory is available at our warehouse. If you need the in stock item before the preorder, please make a separate purchase. For preorder shipping dates, please check the product description section. Some gift cards and promotions may not be available for preorders.
Customer Reviews
Overall rating: 4.3 / 5 from 41 reviews.
I am 5'11" and weigh 205 lbs. The outfit fits me quite snug, so I would recommend keeping that in mind when choosing your size. That said, the fabric is very soft and flexible, which still makes it comfortable to wear. I really like that it has a zipper, since it makes it more practical and comfortable to put on and take off.
I'm 5/10" about 150lbs and the Medium fit perfectly. I love how it has a full zipper up, and the zipper is elegantly covered. The material is very nice, out of the different rompers they offer I feel like this one is the most comfortable on the skin. I paint on my clothes, and painted this romper for a DEVO concert. These rompers are perfect for shows and raves ^_^
The zipper on this is a game changer. I own 5 different styles and this is my favorite thus far. I love the feeling of the material too.
I absolutely love this jumper. The large fits me perfectly, I'm 6ft, 175 lbs, 33" waist. The material is soft and luxurious, with an excellent drape quality to it. Getting tons of compliments wearing it.
I am so pleased with this romper! I've bought some before from different companies and the proportions are always off. I love the length of the shorts. It fits perfectly.
Love it
Love the new arrival zip up romper!
Slightly tighter than expected, but I’m happy with it
Love it
I felt the photos were misleading. The fit is much tighter than it appears, and the color was darker. I also expected the texture to be more silky.
I absolutely love this romper! The fit, material, etc. is just chefs kiss! Can't wait to wear this to my next festival.
Torso is too long for someone 5’10”
Love the fit and look. So comfortable.
I used your "what size do I need" on the website and it was determined that I needed a 3XL. That's what I ordered but it is too small. I did not try on the other romper I ordred.
Fast shipping. Fits great and made well! Thank you!
I was shocked that it actually fit perfectly, but it did. The shoulders are the perfect width, the length is right, the waist is perfect. Grateful for slight stretch in the fabric to accommodate non-model body curves. I didn’t think I’d like a romper, but it looks perfect and I can’t wait to wear it somewhere.
Just received mine and tried it on. Fits perfectly. I'm 5'6", 146lbs and ordered a small. It's polyester so I don't anticipate it will shrink in the dryer. But, it is something I definitely need to avoid. As I said, it fits perfectly as is. Nice heavy weight material. Can't wait to wear it out.
Glad I sized up!
It looks great in the pic but it’s an odd fit, it’s good in the legs, tight fitting in the middle and the top and sleeves are really big, not happy with the purchase.
It's cute
I struggled to get it on and off but otherwise it was good!!
The color isn’t exact and the quality is less than expected. I wish I would’ve saved my money before purchasing. They wouldn’t exchange it, only offer store credit and then made me pay extra plus shipping when it didn’t fit right. A very meh experience.
Putting it on is like putting on a silk glove.
Love the look and feel of this, but how is this an XXL?? You all need to work on your sizing
Nice material. Fits very well
Arrived quickly and fits well. Nice, unique color.
More rompers with zippers please!
very stylish. Quality construction. I will definitely be purchasing other colours.
The person is shirt torso end, but still loves the romper.
I like it , It’s comfortable,
Never received product and I expressed when I needed it by to customer support and they didn’t care and said I couldn’t have any action until the 18th
👍🏻
Coolest thing I own.
Zipper is a huge plus. Great color and material.
The fabric is nice and the style is cool. But I bought a large and it fits me very slim. I’m typically a Large in American sizes, so this romper sizes might be more Asian sizes. I decided to keep it but not running to buy a new one soon.
I purchased this in medium and it was a little big, bulging in the front. I purchased this again in small to correct that issue (did not return the medium) and it was still bulging in the front. I think it's the zipper. I tried to shrink both the small and the medium in the wash, but that didn't help. I originally bought the olive green and while it's made of the same material, the small was way too small and the buttons cracked/broke off when trying to press it to remove the wrinkles. I'm just not having luck finding a version/size that fits right on me. I've bought three at this point, not returning any, hoping one would work out, but I just can't get there.
It’s a slim fit but wasn’t too bad. I wear a large but had to get a XL… but this look here is just simple and not like all outz Like it just for a day out or a night out with friends
I ordered an L which should have fit technically based on the size guide, but was a bit small, so exchanged for an XL (had to pay for return shipping unfortunately). I got the XL and it’s STILL too small. At this point I can’t dump any more money into this project, and the company doesn’t allow refunds so I’m out about $92 altogether and have a romper I will have to donate.
Probably should have ordered and XL. I will gift this one and reorder.