A one-piece skips the two-piece matching problem entirely no separate top and bottom to coordinate, just one continuous piece worked in a chevron stripe pattern from the halter neckline down through the legs. The zigzag comes from a cluster stitch worked in wedges, shifting color every few rows for the striped effect shown here in teal and hot pink. If you’d rather build a matching set from two separate patterns instead, the swimsuit pattern for summer is another single-piece option worth comparing.
Crochet Swimwear One Piece
The chevron shaping happens through built-in increases and decreases at each color change, which is what gives the stripes their zigzag instead of running straight across. Small tassels finish the side ties at the hip, a detail worth keeping if you want the retro feel of the original to come through. Prefer separates instead of one continuous piece? The bikini top and bottom set uses a similar halter-strap construction across two pieces instead of one.
Materials
- Yarn in two colors or one color of choice
- 3.5 mm crochet hook
- Scissors
- Yarn needle
- Stitch markers
- Tape measure
Stitch Reference Guide
Pattern Instructions
Bottom Pieces Make 2
- Measure around your waist and divide the measurement by two to determine the width of each piece
- Chain 64 for a medium size or adjust based on your measurement
- Place a stitch marker in the 31st chain to mark the center
- Double crochet in the fourth chain from the hook
- Chain 2 skip 2 stitches and work 2 double crochets in the next stitch
- Repeat chain 2 skip 2 and 2 double crochets until reaching the center marker
- In the marked stitch work 2 double crochets chain 2 and 2 double crochets
- Continue the same pattern to the end of the row
- New to crochet and not sure how to read a pattern yet? The video tutorial below will guide you through it step by step, you’ve got this!
Bottom Rows 2 to 15
- Work the same double crochet cluster pattern across the row
- Change the spacing to chain 1 between clusters to keep gaps small
- Always work 2 double crochets chain 2 and 2 double crochets in the center chain space
- Alternate finishing rows with one or two double crochets to maintain straight edges
- Continue until each triangle reaches the desired height
Crotch Area
- Attach yarn to the second space from the center of one bottom piece
- Work the double crochet cluster pattern across the center section only
- Continue for 8 to 9 rows depending on desired width
- Attach the end of the crotch section to the second bottom piece using slip stitches or single crochet on the wrong side
Upper Part Top Section
- Construct the top using the same triangle method as the bottom pieces
- Follow the same increase pattern used previously
- Continue working until a total of 24 rows are completed
- Ensure both sides remain symmetrical
Joining Top and Bottom
- Lay the top and bottom pieces with wrong sides facing up
- Align the center points carefully before joining
- Attach yarn and join using double crochet clusters bridging both pieces
- Continue joining evenly across the width
Straps and Finishing
- Attach yarn to each top corner to create neck straps
- Chain and work double crochets along the chain to form a sturdy strap
- Continue until straps are long enough to tie comfortably
- Attach yarn to the bottom corners to create side straps
- Chain long cords that can be crisscrossed and tied
- Add tassels to strap ends if desired for decoration
- Weave in all loose ends securely
Understanding the Construction
- The shaping comes from the center increase.
- Each row grows outward from that marked stitch.
- Working 2 double crochets chain 2 and 2 double crochets in the center space creates a controlled expansion that forms the triangle.
- If your triangle starts to curve or cup, tension is usually the cause.
- Keep your chain spaces relaxed and consistent.
- The center increase must sit flat.
- If it pulls inward, loosen slightly.
- If it flares too much, tighten your chain spacing gently.
- Switching from chain 2 to chain 1 between clusters reduces the openness of the fabric.
- This keeps coverage secure while maintaining airflow.
Fit and Sizing Guidance
- Waist Measurement: Measure snugly but not tightly. Dividing the waist measurement by two ensures each bottom piece forms half of the garment. If your yarn stretches after blocking or wearing, consider subtracting 1 to 2 cm from your starting width.
- Triangle Height: Height determines coverage. Try the triangle against your body as you work. The final row should reach the desired rise without stretching excessively.
- Crotch Width: The 8 to 9 rows create moderate coverage. Add rows if you prefer more width. Keep the stitch pattern consistent so the section blends smoothly into both sides.
- Top Fit: The top triangles should be large enough to cover fully without strain. If increasing to 24 rows feels too small or too large for your size, adjust row count evenly on both sides.
Stitch and Shaping Clarity
- Cluster Pattern: The repeated section is chain space then 2 double crochets. Think of it as creating small V shapes across the row.
- Center Increase: The center is always 2 double crochets chain 2 and 2 double crochets in the same space. That chain 2 in the center is critical. It gives the triangle room to open flat.
- Straight Edges: Alternating one or two double crochets at the row edges keeps the sides aligned. If edges begin slanting, check that you are finishing consistently.
- Symmetry: Count rows frequently. Both triangles must match exactly in stitch count and height to avoid twisting when joined.
Beginner Notes
- Even experienced crocheters benefit from marking the center carefully. If the marker shifts, shaping becomes uneven.
- Count clusters instead of stitches. Clusters are easier to track visually and reduce counting mistakes.
- Lay your work flat every few rows. Visual inspection prevents large corrections later.
Troubleshooting
- Triangle curling inward: Your center chain space may be too tight. Loosen your tension in the chain 2.
- Edges flaring outward: Your edge stitches may be increasing accidentally. Ensure you are not adding extra clusters at the start or end.
- Crotch area pulling: The section may be too narrow. Add one or two additional rows before attaching.
- Top and bottom not aligning: Recheck center placement before joining. The marked center must match on both pieces.
Joining and Finishing Notes
- Join with consistent tension. Pulling too tightly while bridging the top and bottom can cause puckering.
- When making straps, test length before fastening off. Yarn stretches slightly with wear, especially cotton blends.
- Weave in ends in multiple directions inside cluster stitches for security. Because this is a fitted garment, reinforcement matters.
- Block lightly if needed to even out stitches, but avoid over-stretching the triangle points.
