Summer Raglan Baby Romper

Top-down, knitted flat on two needles — sizes 0–3 (3–6, 6–9) months

A seamless-looking short-sleeve romper for warm weather, worked entirely flat on two straight needles and seamed. Raglan yoke, Henley button placket (easy dressing), short legs, and overlapping crotch flaps for diaper changes. Soft stockinette with ribbed edges — no bulky fabric against baby skin.

Skill level: Intermediate (raglan increases, buttonholes, picking up stitches, seaming)

Sizes

0–3 (3–6, 6–9) months

Instructions are written for the smallest size, with larger sizes in parentheses. When only one number is given, it applies to all sizes.

To fit chest: 16 (18, 20)" / 40.5 (45.5, 51) cm

Finished measurements

• Chest: 18 (20½, 22¼)" / 45.5 (52, 56.5) cm, with ~2" / 5 cm positive ease
• Yoke / raglan depth: 4¾ (5, 5¼)" / 12 (12.5, 13.5) cm
• Underarm to crotch: 6½ (7½, 8½)" / 16.5 (19, 21.5) cm
• Shoulder to crotch: 11¼ (12½, 13¾)" / 28.5 (32, 35) cm
• Leg length: 2 (2¼, 2½)" / 5 (5.5, 6.5) cm
• Short sleeve length (underarm to hem): 2 (2¼, 2½)" / 5 (5.5, 6.5) cm
• Back neck width: 2¾ (3½, 4)" / 7 (9, 10) cm

Yarn

Worsted weight (CYC 4), cotton, cotton blend, or superwash wool. Must be soft and machine-washable.

Yardage: 250 (320, 400) yd / 230 (295, 365) m
Shown equivalent: 2 (2, 3) skeins of 100 g / 180 yd (165 m) cotton worsted

Do not use scratchy wool or novelty yarns. Parents need easy care — choose a fiber that can go in the washer.

Needles

• US 8 / 5 mm straight needles (main fabric)
• US 7 / 4.5 mm straight needles (ribbing and bands)

Or size needed to obtain gauge.

Notions

• 4 stitch markers
• Stitch holders or waste yarn
• Tapestry needle
• 6 buttons, ½" / 12 mm (3 for yoke, 3 for crotch)
  or 3 yoke buttons plus plastic snap tape / 3 snaps for the crotch (more practical for diapers)
• Sewing needle and extra-strong thread for buttons

Gauge

18 sts and 24 rows = 4" (10 cm) in stockinette stitch on US 8 / 5 mm, after blocking.

4.5 sts / inch; 6 rows / inch.

Check gauge. A 1" difference in chest is a full size for a baby.

Abbreviations (US)

• BO — bind off
• CO — cast on
• k — knit
• k2tog — knit 2 together (right-leaning decrease)
• M1L — make 1 left (lift strand between sts from front to back, knit through back loop)
• M1R — make 1 right (lift strand between sts from back to front, knit through front loop)
• p — purl
• pm — place marker
• RS — right side
• St st — stockinette stitch (knit RS, purl WS)
• st(s) — stitch(es)
• WS — wrong side
• yo — yarn over

Notes

• Worked flat, on two straight needles, in five pieces: Back, Left Front, Right Front, two Sleeves. Seamed after knitting.
• Raglan increases are worked on every RS row. All pieces must have the same number of raglan rows so the seams match: 28 (30, 32) rows.
• Button bands are 5 sts in garter stitch (knit every row).
• Buttonholes sit on the Right Front (as worn).
• Below the yoke, overlap the front bands and sew them closed so the body is a pullover. The 3 yoke buttons plus a stretchy neck are enough to dress baby; crotch flaps handle diapers.
• Selvedge: slip the first stitch purlwise with yarn in front on every row for a clean seam edge, or knit it — be consistent.
• Cotton grows slightly after washing. Block pieces before seaming.
• Safety: sew buttons on with extra-strong thread, through all layers, and knot on the inside. A loose button is a choking hazard. Snaps are safer at the crotch.

Stitch patterns

Stockinette stitch (flat)
RS: Knit.
WS: Purl.

Garter stitch (flat)
Knit every row.

1×1 Rib (flat, even sts)
Every row: *K1, p1; repeat from * to end.

Buttonhole (5-st garter band, RS)
K1, k2tog, yo, k2.

Instructions

BACK

With US 8 / 5 mm needles, CO 12 (16, 18) sts.

Set-up row (WS): Purl.

Raglan yoke

Row 1 (RS, increase): K1, M1R, knit to last st, M1L, k1.
Row 2 (WS): Purl.

Repeat Rows 1–2 13 (14, 15) more times — 14 (15, 16) increase rows total.

Stitch count: 12 + 28 = 40 (16 + 30 = 46, 18 + 32 = 50) sts ✓
Piece measures 4¾ (5, 5¼)" / 12 (12.5, 13.5) cm from CO. This is the underarm.

Body

Work even in St st until piece measures 6½ (7½, 8½)" / 16.5 (19, 21.5) cm from underarm, ending with a WS row.

Divide for legs

Next row (RS): K 16 (18, 20) sts and place these sts on a holder for the Left Leg. BO the next 8 (10, 10) sts for the crotch (8 + 10 + 10 crotch ✓). K remaining 16 (18, 20) sts for the Right Leg.
16 + 8 + 16 = 40 (18 + 10 + 18 = 46, 20 + 10 + 20 = 50) ✓

Right Leg

Continue on the 16 (18, 20) Right Leg sts.

Work 6 (8, 9) rows even in St st.

Change to US 7 / 4.5 mm. Work 6 rows in 1×1 rib.
BO in rib.

Left Leg

With RS facing, return 16 (18, 20) held sts to US 8 / 5 mm needle. Rejoin yarn.

Work 6 (8, 9) rows even in St st.

Change to US 7 / 4.5 mm. Work 6 rows in 1×1 rib.
BO in rib.

LEFT FRONT

(Wearer’s left. Band sits at center front; raglan sits at the armhole.)

With US 8 / 5 mm needles, CO 9 (11, 12) sts.

Set-up row (WS): K5 (garter band), purl to end.

Raglan yoke

Row 1 (RS, increase): K1, M1R, knit to last 5 sts, k5 (band).
Row 2 (WS): K5, purl to end.

Repeat Rows 1–2 13 (14, 15) more times — 14 (15, 16) increase rows.

Stitch count: 9 + 14 = 23 (11 + 15 = 26, 12 + 16 = 28) sts ✓
Raglan edge is 28 (30, 32) rows — matches Back ✓

Body

Keeping 5 sts at the center-front edge in garter and the remainder in St st, work even until piece measures 6½ (7½, 8½)" / 16.5 (19, 21.5) cm from underarm, ending with a RS row (so the band edge is ready to bind off on WS).

Divide for leg

Next row (WS): BO 7 (8, 8) sts (inner crotch edge, includes the band), purl to end.
16 (18, 20) sts remain ✓

Left Leg

Work 6 (8, 9) rows even in St st.

Change to US 7 / 4.5 mm. Work 6 rows in 1×1 rib.
BO in rib.

RIGHT FRONT

(Wearer’s right. This band carries the yoke buttonholes.)

With US 8 / 5 mm needles, CO 9 (11, 12) sts.

Set-up row (WS): Purl to last 5 sts, k5 (garter band).

Raglan yoke

Row 1 (RS, increase): K5 (band), knit to last st, M1L, k1.
Row 2 (WS): Purl to last 5 sts, k5.

Repeat Rows 1–2 13 (14, 15) more times — 14 (15, 16) increase rows.

Stitch count: 9 + 14 = 23 (11 + 15 = 26, 12 + 16 = 28) sts ✓

Buttonholes — work on RS rows 3, 8 (9, 9), and 13 (14, 15):
On those RS rows, work the 5 band sts as: k1, k2tog, yo, k2, then complete the row as established (including the raglan increase).
Three buttonholes sit inside the 14 (15, 16) RS rows ✓

Body

Keeping 5 sts at the center-front edge in garter and the remainder in St st, work even until piece measures 6½ (7½, 8½)" / 16.5 (19, 21.5) cm from underarm, ending with a WS row.

Divide for leg

Next row (RS): BO 7 (8, 8) sts (inner crotch edge, includes the band), knit to end.
16 (18, 20) sts remain ✓

Right Leg

Work 6 (8, 9) rows even in St st, beginning with a WS row.

Change to US 7 / 4.5 mm. Work 6 rows in 1×1 rib.
BO in rib.

SLEEVES (make 2)

With US 8 / 5 mm needles, CO 8 (8, 10) sts.

Set-up row (WS): Purl.

Raglan cap

Row 1 (RS, increase): K1, M1R, knit to last st, M1L, k1.
Row 2 (WS): Purl.

Repeat Rows 1–2 13 (14, 15) more times — 14 (15, 16) increase rows.

Stitch count: 8 + 28 = 36 (8 + 30 = 38, 10 + 32 = 42) sts ✓
Raglan edge is 28 (30, 32) rows — matches body pieces ✓
Upper-arm width: 36 (38, 42) sts = 8 (8½, 9¼)" / 20.5 (21.5, 23.5) cm ✓

Short sleeve

Work 4 (6, 6) rows even in St st.

Decrease row (RS): Knit, decreasing 8 (8, 10) sts evenly across the row.
36 − 8 = 28 (38 − 8 = 30, 42 − 10 = 32) sts ✓

Change to US 7 / 4.5 mm. Work 6 rows in 1×1 rib.
BO in rib.

Finishing

Block all pieces to measurements. Cotton especially benefits from a wet block; let dry fully before seaming.

Raglan seams

With RS together (or mattress stitch from the RS), sew each sleeve raglan edge to the matching Front and Back raglan edges. Four raglan seams. All seams are 28 (30, 32) rows / 4¾ (5, 5¼)" — they must match without easing ✓

Close any small hole at the underarm with the yarn tail.

Front bands below the yoke

Overlap the Right Front band over the Left Front band, from just below the last buttonhole to the crotch divide. Whipstitch or mattress-stitch through the overlapping 5-st bands, catching both layers. The body is now closed like a pullover. Chest circumference: 40 (46, 50) back + 18 (21, 23) + 18 (21, 23) fronts + 5 visible band = 81 (93, 101) sts = 18 (20¾, 22½)" before seaming ease ✓

Side seams and inner legs

Sew each side seam from underarm to the top of the leg.

Sew each inner-leg seam from the rib hem up to the crotch bind-off. Do not join the front and back crotch bind-off edges — that opening is for the flaps.

Sleeve seams

Sew each sleeve seam from cuff to underarm.

Neckband

With US 7 / 4.5 mm needles and RS facing, beginning at the Right Front band edge, pick up and knit:

• 5 sts across the top of the Right Front band
• 4 (6, 7) sts along Right Front neck
• 1 st in the raglan seam
• 8 (8, 10) sts along Right Sleeve
• 1 st in the raglan seam
• 12 (16, 18) sts along Back neck
• 1 st in the raglan seam
• 8 (8, 10) sts along Left Sleeve
• 1 st in the raglan seam
• 4 (6, 7) sts along Left Front neck
• 5 sts across the top of the Left Front band

Total: 50 (58, 66) sts ✓

Work 6 rows in 1×1 rib.
On Row 3 (RS), work a buttonhole above the Right Front band: work 2 sts, k2tog, yo, rib to end.

BO loosely in rib.

Crotch flaps

Back flap (this one tucks between the legs, like a onesie):
With US 7 / 4.5 mm and RS facing, pick up and knit 16 (18, 18) sts along the back crotch bind-off, catching 4 (4, 4) sts from each inner-leg edge and 8 (10, 10) across the bind-off.
Work 10 rows garter stitch (about 1¼" / 3 cm). BO.

Front flap:
Pick up and knit 16 (18, 18) sts along the two front inner bind-offs.
Work 6 rows garter stitch.
On Row 3, make 3 evenly spaced buttonholes: k2 (3, 3), [yo, k2tog, k3 (3, 3)] twice, yo, k2tog, k2 (3, 3).
16 sts: 2 + (2+3) + (2+3) + 2 + 2 = 16 ✓
18 sts: 3 + (2+3) + (2+3) + 2 + 3 = 18 ✓
BO.

The back flap overlaps the front flap.

Buttons

Sew 3 buttons to the Left Front band, opposite the yoke buttonholes.
Sew 3 buttons to the front crotch flap, opposite the back-flap overlap — or install 3 plastic snaps / snap tape (recommended for daily diaper changes).

Sew every button with extra-strong thread, through all layers, and finish with a surgeon’s knot on the inside. Tug-test each one.

Weave in ends

Weave all ends on the WS. Trim. Wash on a gentle cycle and lay flat to dry.

Schematic (inches / cm)

                    neck ~ 10–12" opening with placket
                 _____________
                /    yoke     \          raglan 4¾ (5, 5¼)"
               /               \
        ______/                 \______   sleeve 2 (2¼, 2½)"
       |                           |
       |         chest             |      18 (20½, 22¼)"
       |     6½ (7½, 8½)"          |
       |                           |
        \         crotch          /       flaps overlap here
         \      /         \      /
          |____|           |____|         legs 2 (2¼, 2½)"

Care

Machine wash cold, gentle cycle. Lay flat to dry. Do not use fabric softener on superwash wool. Recheck buttons after every wash.