A red bikini top with white contrast edging is one of those classic summer combinations that photographs beautifully and wears even better and this shaped-cup construction gives it a fit that’s actually supportive rather than just decorative. The cups are worked flat with increases, which keeps the shaping approachable for beginners. If you want to pair it with a matching bottom, the tie-side swimsuit bottoms are a natural companion pattern worth bookmarking alongside this one.
Crochet Bathing Suit
The white picot edging along the cup seam and band is what elevates this beyond a basic triangle top it’s a small finishing detail that adds a vintage feel without requiring any advanced techniques. Halter tie straps mean you can adjust the fit after blocking, which matters more than people think with swimwear cotton. For another shaped-cup bralette that takes the construction in a slightly different direction, the crochet bralette with cups and mesh trim is worth a look.
Before You Start
This pattern is written in a straightforward way, but it helps to understand what each section is doing:
- Base square (rectangle): creates the width and height that determines how much coverage you’ll have.
- Cup shaping: uses the side edges of those rows to form a curved cup. The first shaping row adds structure, then the next rows let the curve happen naturally.
- Bottom band: gives spacing to lace a long strap through, and helps the cups sit neatly.
- Edging: adds a finished look and helps the edge hold its shape.
- Straps: made with a smaller, firmer stitch pattern so ties don’t stretch out too quickly.
Materials
- Yarn of your choice
- 2.5 mm crochet hook for the cups and edging
- 3.5 mm crochet hook for the straps
- Measuring tape
- Scissors
- Yarn needle
Skill Notes You’ll Be Glad You Read
Stitch expectations (so you don’t second-guess yourself)
- The cups are mostly double crochet, so the fabric will drape and shape.
- The straps are single crochet in the back loop only, which creates a slightly ribbed, flexible strap that ties well.
Measurement that matters most
The very first chain determines the width across your chest (the span the cups will sit on). If that chain is too short, the top will pull inward. If it is too long, the cups can drift outward.
A helpful approach:
- Measure the width across your chest where you want the cups to sit.
- Crochet the starting chain, then lightly stretch it and check the width before you commit.
Pattern Notes for Clean Results
- Turning chain clarity: When you chain 3 to start a row, treat it like a stitch. That’s why you place the last double crochet into the top of that turning chain later. It prevents the “leaning edge” problem.
- Side-edge stitches: When you crochet into the side of rows, you’re working into row-ends, not clear stitch tops. That’s why the pattern tells you to place 2 double crochets into the side of each row—it fills the space evenly and avoids gaps.
Pattern
Creating the Base Square
- Start with a slip knot and chain 16 or the number needed to match the width of your chest measurement
- Chain 3 to count as the first double crochet
- Work one double crochet in each chain across
- Chain 3, turn, and work one double crochet in each stitch across
- Place the final double crochet into the top of the turning chain to keep edges straight
- Repeat rows until the base reaches your desired height, approximately 7 rows
- If you’re a beginner and crochet patterns feel confusing, start with the video tutorial below, it’s the easiest way to learn as you go!
Extra clarity for this section
- That “approximately 7 rows” is your coverage control. Fewer rows makes a smaller cup; more rows gives more coverage.
- Watch your edges: placing the last double crochet into the turning chain is what makes both side edges neat, and neat side edges matter because you will crochet into them to shape the cup.
Shaping the Cup
- Turn the work to the side edge of the completed rows
- Chain 3 to begin the first side row
- Place 2 double crochets into the side of each row
- At the center corner of the original foundation chain, place 3 double crochets in the same stitch
- Continue placing 2 double crochets into the side of each row on the opposite edge
- For the next 6 to 7 rows, work one double crochet into every stitch across
- Do not increase in the center on these rows to allow the cup to curve naturally
What’s happening here (so the shaping makes sense)
- When you “turn the work to the side edge,” you’re now crocheting around the rectangle instead of across it. This is what transforms a flat panel into a cup shape.
- The 3 double crochets at the center corner create the turning point that gives you a rounded base.
- The instruction not to increase in the center for the next rows is important: those even rows allow the fabric to naturally bend into a cup instead of flaring outward.
Common confusion to avoid
- Where exactly is the “center corner of the original foundation chain”?
It’s the corner stitch at the end of your starting chain edge—basically the point where the side edge meets the foundation edge. This is the pivot point for the cup shaping row. - Side stitches feel messy: That’s normal. Row ends don’t look like clear V-stitches. Focus on spacing your 2 double crochets evenly into each row side rather than hunting for a “perfect” insertion spot.
Bottom Band and Edging
- Attach yarn to the bottom edge of the cup
- Chain 3 and place one double crochet in the first space
- Chain 1, skip one space, and place 2 double crochets in the next space
- Repeat the chain 1 and 2 double crochet pattern across the bottom edge
- Attach contrasting yarn to any edge of the cup
- Work 3 single crochets, then chain 3 and slip stitch back into the base stitch
- Repeat this edging pattern evenly around the cup
Why this bottom band works
- The chain 1 spaces you create are not just decorative. They are the holes you will weave the long strap through later.
- Skipping a space each time keeps the band from becoming too stiff or bulky.
Edging placement help
- “Any edge” gives you flexibility, but most crocheters like to start near a less noticeable spot (like near the bottom corner), so the join blends in.
- Keep the edging even. If you cram too many edging repeats into a short area, the edge will ripple. If you space them too far apart, it can look sparse.
Straps and Assembly
- Switch to the 3.5 mm hook and attach yarn at the top point of the cup
- Chain 2 and single crochet into the back loop only
- Chain 2 and single crochet into the previous single crochet
- Repeat this strap pattern until the neck strap is long enough to tie comfortably
- Create a separate long strap using the same chain 2 and single crochet method
- Weave the long strap through the chain 1 spaces along the bottom band of both cups
Secure ends and weave in all loose yarn to finish the bikini top
Strap clarity (this is the section people reread)
- You are making a narrow strap by repeatedly chaining and then anchoring with a single crochet.
- “Single crochet into the previous single crochet” means you’re working into the last single crochet you made, building a compact, linked strap.
Fit adjustment tips that don’t change the pattern
- Neck strap length: Make it long enough that you can tie a bow without strain. If it barely ties, it will feel tight and pull the cups upward.
- Long strap length: This controls how snug the bottom band sits. If you like a secure fit, make it longer than you think you need so you have tying room.
Fit and Sizing Guidance
Because this is a made-to-measure start, you can fine-tune fit using only these parts of the pattern:
- More coverage: Add a couple more rows in the base square before shaping.
- Less coverage: Stop a couple rows earlier.
- Wider set cups: Start with a slightly longer foundation chain width.
- Closer set cups: Start with a slightly shorter foundation chain width.
After you finish the first cup, hold it against your body (or pin it to a bra) and check:
- Is the height enough?
- Does the curve sit smoothly, or does it flare?
If it flares, the usual cause is too many stitches picked up on the sides. Take your time placing the “2 double crochets into the side of each row” neatly and evenly.
Beginner Notes That Prevent Frustration
- Count rows, not guesses. If you make one cup with 7 rows and the other with 8, you’ll see it immediately.
- Use stitch markers on the cup tip and bottom corners (even if you don’t normally). It helps you attach straps in the same place on both cups.
- Choose yarn that feels comfortable against skin. Since this is a bikini top, many crocheters prefer cotton or a smooth blend to avoid itch.
Troubleshooting
My edges look wavy
- Check the “final double crochet into the turning chain” step. Missing that makes edges uneven, which affects the cup shaping.
The cup is too flat
- Most often, the base square height is too short. Add a row or two next time for more depth.
- Also make sure you did the center corner step: the “3 double crochets in the same stitch” is a big part of shaping.
The cup flares outward instead of curving
- Side stitches may be uneven or too loose. Focus on consistent tension while placing 2 double crochets into each row side.
- Make sure you are not increasing in the center for the 6 to 7 rows after the first shaping row.
The bottom strap doesn’t sit nicely
- When weaving through the chain spaces, keep the strap flat and untwisted.
- Even tension matters: if you pull tightly in one section and loosely in another, the bottom edge will pucker.
Finishing Notes
- Weave in ends securely, especially at strap joins and corners. Ties and edges get the most stress.
- If you want extra stability without changing the pattern, weave in ends along the strap path rather than straight across. It reinforces the tie area.
