Window width × 2 to 2.5 (for fullness) × number of panels for the total fabric width. Then multiply the drop length by the number of widths needed, and add 30 cm for hems and headers. Use the calculator above with piece length = drop + 30 cm and piece width = window width × fullness.

Add 10–25%. Napped fabrics like velvet and corduroy must have all pieces oriented the same way, which uses more length. Plaids and stripes need extra so you can match patterns at seams. One-way prints (animals, text, scenes) need a single orientation too.

For cotton, linen, denim and wool, yes — they shrink, and shrinking after sewing is heartbreaking. Pre-wash the fabric the same way you'll wash the finished garment. If you don't pre-wash, use the higher end of the shrinkage estimate above so you don't run short.

A quilting term: 18 × 22″ (≈46 × 56 cm). It's a half-yard cut from quilting cotton (~110 cm wide), then halved across the width — giving a square-ish piece more useful than the long thin "skinny quarter".

This calculator assumes you're cutting multiple identical rectangles. A pattern envelope's number is based on the actual layout of all the differently-shaped pieces nested together — work the calculator can't replicate. For full garments, use the Garment fabric estimator or trust the pattern envelope.

Older patterns and US patterns use imperial inches; European patterns use metric. Many modern patterns include both, which means you'll regularly need to convert between them when following directions or comparing pattern envelopes.

Yes — 1 inch is exactly 2.54 cm by international agreement. The calculator shows two decimal places, which is well below the cutting precision of any home sewist (a sharp pair of shears is accurate to about 1 mm).

Yes — that's the standard rounding used on commercial patterns. The exact value is 1.59 cm, so the difference is under 1 mm and well within fabric stretch and cutting variance. The same applies to 1/4″ ≈ 6 mm (exact 6.35 mm) and 3/8″ ≈ 1 cm (exact 9.5 mm).

Type either 1 1/2 with a space, or 1-1/2 with a hyphen — both work. You can also use a decimal (1.5) or just the fraction (3/2). The calculator parses any of these.

Bias-cut strips stretch and curve. Straight-grain binding only works on perfectly straight edges — try it on a curved hem or armhole and you'll see it bunch up. Anywhere there's a curve, bias is the right choice.

About 5–10%, mostly in the corners. It's one of the more efficient methods — far better than cutting individual strips and joining them, which can waste 20–30% in seam allowances.

Yes — common widths are 1.3 cm (single fold) and 6 mm (double fold finished). Pre-made saves time but limits your colour, fibre, and pattern choices, and is usually polyester rather than the same fabric as your garment.

Always. Necklines and armholes are curved — bias hugs them. A 2.5–3 cm cut strip yields a 6 mm finished double-fold bias binding, the standard for clean inside finishes on curves.

Pattern designers do "marker making" — fitting all the differently-shaped pieces together onto the fabric like a jigsaw. The bodice tucks into the curve under the sleeve, sleeves nest into the skirt's spare width. A calculator can only approximate by treating each piece as a rectangle.

Tick the plus-size box for ~15% more. For very large sizes (UK 24+), add another 0.25–0.5 m to be safe — pieces grow in both length and width, but width grows faster than the calculator's linear adjustment captures.

Use the special-fabric dropdown. Napped fabrics (velvet, corduroy, fleece) have a direction — the pile catches light differently end-to-end — so all pieces must be cut facing the same way. That uses more length than a non-napped layout.

Pick "plaid / striped" — adds 25%. Matching plaid at seams means cutting each piece so its plaid lines up with the next one, which forces you to cut every piece individually rather than from folded fabric, and waste fabric to align repeats.

The bases are for adults. As a starting point, halve the estimate for primary-school age and add a little. For a child's full-skirted dress at 150 cm wide, expect around 1.5–2 m rather than the 4 m the adult estimator returns.

Button diameter plus 3 mm (1/8″) for ease. For thick or domed buttons, add another 2–3 mm so the buttonhole isn't strained around the button's profile.

On a shirt placket, 1.5–2 cm below the collar stand. On a dress front, 5–7 cm below the neckline finish so the neckline doesn't gape. The calculator above lets you set this directly with the "top button from top edge" field.

It's a hangover from when wealthy women's clothes were buttoned by maids. Maids stood facing the wearer, so buttons on the wearer's left were on the maid's right — the side of their dominant hand. Most pattern designers still follow the convention.

Horizontal for plackets and waistbands (the button slides to the corner under stress, holding firm). Vertical for narrow plackets and shirt fronts where there's less side-to-side strain. The calculator's spacing works for either orientation.

Every 6–8 hours of active sewing, or at the start of any project where stitch quality matters. A dull needle is the #1 cause of skipped stitches, snagging, and pulled threads — and changing one is a 30-second job.

Universal has a slightly rounded point that handles most wovens fine. Microtex (sometimes labelled "Sharp") has a very fine, sharp point — better for densely-woven fabrics like silk, microfibre, oilskin, and high-thread-count cottons where a Universal might deflect.

You can on the body of the garment, but you'll likely break it on thick seam intersections. Jeans needles have a stronger shaft and a sharper point designed for denim. Use one whenever you're crossing more than three layers of medium fabric.

Ballpoint or Stretch — they have a rounded tip that slips between the yarns rather than piercing them, preventing skipped stitches and pulled runs in the knit. Stretch needles also have a special "scarf" that helps the bobbin thread catch reliably on stretchy fabric.

Schmetz Universal 80/12 — sews 90% of dressmaking fabrics adequately. Pair it with a Stretch 75/11 for knits and a Jeans 100/16 for denim and you'll cover almost everything.

Polyester sew-all — Gütermann's is the most widely-stocked in the UK. It's strong, doesn't shrink, works on virtually anything from chiffon to denim, and comes in hundreds of colours. A small starter set covers most projects.

For most sewing, yes — same fibre, same weight, same colour. Mismatching causes tension issues. Exceptions: very fine fabrics (use a finer bobbin to reduce seam bulk), and heavy topstitching (use a regular thread in the bobbin since topstitch thread doesn't always run smoothly in a bobbin case).

30 wt or 40 wt thread (Gütermann's "Topstitch" or "Jeans" lines), with a topstitching needle (size 100/16) and a longer stitch length (3–3.5 mm). The chunkier thread is what gives that classic visible "denim look".

Cotton on cotton is traditional and behaves more naturally as the quilt is washed and aged. Polyester is fine and stronger but doesn't shrink with the fabric, so heirloom quilters generally prefer cotton. For piecing, 50 wt cotton (Aurifil, Mettler Silk-Finish) is the go-to.

Yes — sergers run through 4 spools at once, so use the larger 2,500–5,000 m cones rather than the 100 m sewing-machine spools. Polyester sew-all weight is fine; some sergers prefer specifically labelled "overlocker thread", which is slightly thinner and runs more smoothly through the loopers.

Three usual suspects: tension is too tight, stitch is too short for the fabric, or thread is too thick for the fabric. Try lengthening the stitch first (try 3 mm), then loosening upper tension by half a number. A fresh needle and the right needle type also help.

3–3.5 mm with topstitching thread and a Jeans needle (size 100/16). The slightly longer stitch shows the topstitch thread better and gives jeans their characteristic visible-stitching look. Use a regular sew-all in the bobbin.

Stretchy fabrics (a tight straight stitch will pop when the fabric stretches), edge finishing on woven fabrics (raw edges fray less), applique, buttonholes, and decorative work. For knit construction, a narrow zigzag (~1 mm wide × 2.5 mm long) is the standard choice on a regular sewing machine.

Basting is a long temporary stitch (4–5 mm) that you remove after the final seam is sewn. Use it to hold pieces in place before final stitching, especially curved or fitted seams. Loose-tension basting is also how you create even gathers — pull the bobbin thread to draw up the fabric.

Almost always a needle problem — dull, bent, or the wrong type for the fabric. Change the needle first. If that doesn't fix it, check that the needle is fully inserted and the right way round (flat side of the shank to the back on most home machines).

"Do not" — e.g., a crossed-out tub means do not wash, a crossed-out triangle means do not bleach, a crossed-out iron means do not iron. The cross is a strict prohibition; the garment will likely be damaged if you ignore it.

Hand wash is gentler. If your garment shows a "hand in tub" symbol, hand wash is safest, but most modern machines have a "hand wash" or "delicates" cycle that approximates hand-washing — short, gentle agitation, low spin speed, cool water.

One dot = low (max 60 °C), two dots = medium (max 80 °C), three dots = high (max 95 °C). Crossed-out circle-in-square = do not tumble dry. The dots system is the same for ironing — one dot is synthetics, two is wool/silk, three is cotton/linen.

The American ASTM symbols are very similar to ISO 3758 but use letters in some cases (e.g., "W" or "P" inside a circle for solvent type for dry cleaning). Garments sold internationally usually carry both, or the system that applies in the country of sale.

It means "gentle" — one line under a tub means gentle wash cycle; two lines means very gentle / delicate. Same convention applies to tumble drying.

−2 cm to −5 cm for a snug, plump look (typical for new feather-fill pillows). 0 to +2 cm for older flatter pillows or polyester forms. Adjust to taste — try one and see.

If adding piping, increase your seam allowance to 1 cm + the piping width (typically 6–10 mm). Trim piping ends inside the seam allowance so they don't show through.

To give a generous overlap that hides the pillow form regardless of how you settle the cushion. 50% (just half each) leaves a gap when the form is full; 70% wastes fabric.

Only if your finished width fits within your fabric width. A 90 cm wide table with 25 cm drops needs 90 + 50 = 140 cm of finished cloth width, which fits 150 cm fabric. Wider tables or longer drops need pieced fabric.

Avoid running seams down the centre of the table. Plan one full-width centre panel and add equal-width strips on each side to make up the rest. The eye accepts symmetry better than a single off-centre seam.

A double-fold hem (1.5–3 cm) on heavier fabrics, mitred at the corners. For lightweight fabrics, a narrow rolled hem looks delicate and doesn't add bulk. Bonded or fused hems work for "no-sew" cloths but won't survive many washes.

Single notches are usually for the front of a garment, double for the back — but this varies by pattern brand. Trust the layout sheet for orientation, not the notch direction.

For Big 4 commercial patterns (Vogue, Simplicity, McCalls, Butterick), yes — 1.5 cm / 5/8″. For indie patterns, anywhere from 6 mm to 1 cm. Always check the pattern envelope or instruction sheet before cutting.

A horizontal line on the pattern showing where to add or remove length without distorting the design. Cut on the line, then either spread it apart (lengthen) or overlap (shorten) and re-tape before cutting fabric.

1 oz/yd² = 33.906 g/m². To convert GSM to oz/yd², divide by 33.906 (or multiply by 0.0295). To convert oz/yd² to GSM, multiply by 33.906.

European fabric mills usually quote GSM (metric); American mills quote oz/yd² (imperial). Many UK fabric shops quote both. They measure the same thing — area density — just in different units.

No — choose weight to match the project. A 280 GSM denim makes great jeans but would be miserable as a summer dress. Lightweight fabrics drape; heavyweight fabrics structure. Both have their place.

That's the standard flying-geese ratio. Non-2:1 geese exist but they're less common and need different formulas. The calculator above assumes 2:1; for other ratios you'd need to construct the unit differently (often as two right triangles + a square).

Yes — slight inaccuracies always creep in. Trim each completed unit to the unfinished size (finished + ½″ for seam allowances). A flying-geese trimmer ruler makes this much faster than measuring each one.

Two reasons: the centre point where four triangles meet is fussy to align, and all four edges are bias (stretchy). HSTs only have two bias edges. Pressing seams open at the centre helps reduce bulk; pressing the second seam opposite to the first locks the centre point.

An hourglass block is the simplest QST — only two fabrics, with the same colour in opposite triangles. A QST can have up to four different fabrics. "QST" is the technical term; "hourglass" is the named pattern.

It depends on the elastic and the garment. For waistbands: 5–10% smaller than waist. For wrist/ankle cuffs: 10–20% smaller. For pyjamas: as little as 5% (don't want indentations). The calculator above gives you a starting point — adjust to taste.

2–3 cm is standard. Overlap the two ends and zigzag back and forth to hold them firmly. Too short an overlap pulls apart over time; too long is bulky.

Fusible is faster and works well for most projects — collars, cuffs, plackets. Sew-in is better for silk, very lightweight fabrics, and tailored coats where the interfacing softens with body movement.

Place the bumpy (glue) side down on the WRONG side of fabric, cover with a damp pressing cloth, and press (don't slide) for 10–15 seconds. Lift, don't drag. Always test temperature on a scrap first — too hot scorches, too cool doesn't stick.

Three usual causes: (1) too cool an iron — bumps didn't melt; (2) not enough pressure — try harder; (3) the fabric and interfacing have different shrinkage rates — pre-shrink fusible interfacing by soaking in warm water before use.

Pattern sizing was standardised in the 1950s based on bust/waist/hip measurements. Retail sizes have drifted (so-called "vanity sizing") and now run noticeably smaller than pattern sizes. A UK ready-to-wear 12 typically corresponds to a UK pattern size 14 or 16.

Very common — most people don't fit a single size cleanly. Grade between sizes: trace the bust line of one size, the waist of another, the hip of a third, and join them with smooth curves. Most patterns include all the size lines on a single sheet for this reason.

No — children's sizing is based on age (often paired with height) and varies even more by region. This chart is for adult patterns only.

These figures match the standard "Big 4" pattern companies (Simplicity, McCall's, Vogue, Butterick) and most UK indie pattern designers. Individual designers may differ slightly — always check the specific pattern's size chart before cutting.

Only if your skirt has no waistband and pulls on. For a fitted skirt with a waistband, use your actual waist measurement — the band sits at your natural waist with minimal ease. For a pull-on skirt, add 5–10 cm so it stretches over your hips.

A full circle skirt requires a square at least as wide as the outer diameter (2 × outer radius). If your fabric is narrower, you'll need to piece the skirt — typically by cutting it as four quarter-circle wedges and joining them at seams.

Yes — that's why it's a statement skirt. A waist of 70 cm with a 60 cm length needs at least a 145 cm × 145 cm square. Wider hips and longer skirts may exceed standard 150 cm fabric width and need pieced panels.

A full circle has bias on every part of the hem; a half circle has bias on half. Bias hangs heavier and droops more — so full circles drape with more dramatic ripples, while quarter circles fall straighter and are easier to hem evenly.

2.5″ is the most common — gives a 3/8″ finished binding on both sides of the quilt edge. 2.25″ is tighter and better suited to thinner battings. 2″ is the absolute minimum and only works with very thin batting and careful sewing.

Straight-grain (cross-grain) binding works for any quilt with straight edges. It uses less fabric. Bias binding is required for curved-edge quilts (scallop, round) — it stretches around the curves smoothly. Many quilters prefer bias on rectangular quilts too because it wears better.

The calculator above gives strips and yardage. As a rule of thumb: a typical 60 × 80″ quilt needs about ½ yard of binding fabric for cross-grain at 2.5″ strips.

Two reasons: seam allowances (1/4″ × 2 = 1/2″) and the geometry of the diagonal seam. The 7/8″ figure for 2-at-a-time accounts for both. The other methods need more because they involve diagonal seams along multiple edges.

Yes — slight inaccuracies in cutting and seam allowance creep up. Square up each HST to the unfinished size (finished + 1/2″ for seam allowances) using a square ruler. Some quilters cut slightly oversized intentionally to allow trimming.

2-at-a-time when accuracy matters (small HSTs, intricate blocks). 4-at-a-time for medium volume (handle the bias edges with starch). 8-at-a-time when you need a lot of HSTs and don't mind the extra trimming — great for chained-block patterns.

For lined curtains: 15–20 cm (a doubled-over deep hem hangs heavier and looks better). For unlined: 10–15 cm. Add an extra 5 cm if you want the option to lengthen later.

Standard 75 mm (3″) pencil pleat tape needs 10–15 cm of header allowance — enough to fold the top over once and stitch the tape on. Triple-pleat or eyelet tapes vary; check the tape's instructions.

Curtains use a lot of fabric — that's normal. A pair of 2× pencil pleat curtains for a 180 cm window with 220 cm drop in 140 cm-wide fabric typically needs 6–7 m total. Lined curtains roughly double that figure.

Two rows distribute the gathering forces and keep the gathers even. With one row, the fabric tends to twist along the basting line and leave one side fuller than the other. Two rows ~5 mm apart keep the fabric flat and the gathers tidy.

Yes. Heavy fabrics (denim, canvas, heavy linen) gather poorly above 1.5–2× — the bulk distorts the seam. Light fabrics (lawn, voile, batiste) can take 3× or more before they look excessive.

Yes — sewing 1/4″ elastic stretched along the wrong side gives a permanent gathered effect. The "ratio" then depends on how much you stretch: stretching the elastic to 1.5× the length of the channel gives a roughly 1.5× gather.

It means the pattern requires fabric that will stretch to at least 1.25× its relaxed length on the cross-grain. So if you start with 10 cm of fabric, it must comfortably stretch to 12.5 cm. This is typical for fitted t-shirts and tops.

Comfortable stretch — what the fabric will give without distorting or "popping". Pattern designers spec stretch based on comfortable wear, not breaking point.

Hugely. Stretch tells you how far it goes; recovery tells you whether it bounces back. A fabric with 50% stretch but poor recovery will sag at knees and elbows. Press the stretched fabric briefly and let go — it should snap back fully within a second.

Long-arm quilters typically ask for 4″ on each side. If you're quilting at home with a domestic machine, 2–3″ is enough. If you're hand-tying or pin-basting yourself, 2″ works.

Whichever uses less fabric. The calculator picks the cheaper orientation. Many quilters prefer horizontal seams for vertically-oriented quilts because the seam lies more naturally with the quilt's hang.

You can, but the high thread count of sheets makes them harder to needle through during quilting and they don't always wash up the same way as your quilt top. Purpose-made wide-back fabric is the simplest choice.

Decide finished hem circumference and pleat width (typically 2–3 cm). Number of pleats = circumference ÷ pleat width. Cut fabric = 3 × circumference (knife pleats with depth = visible width). Add seam and hem allowances on top.

For traditional knife pleats, yes — depth = visible width gives the classic "fully pleated" look. Smaller depth gives a flatter pleated surface (good on heavy fabric); larger depth gives more swing and movement.

Press at every stage. Mark fold lines with chalk, fold, baste, then press hard with steam (use a damp pressing cloth on delicate fabrics). Some sewists "set" pleats overnight under a heavy book before edge-stitching the top.