Free quilt block designer
Paint a grid with solid squares and half-square triangles, see the block repeated as a whole quilt, then get cutting sizes and yardage for every fabric.
Arrow keys move between squares. Enter or Space paints with the current brush. R turns a triangle, H switches between square and triangle brush, O changes the triangle direction, X swaps fabrics A and B, number keys choose fabric A (with Shift, fabric B).
Click or drag to paint. Tap a triangle again to turn it.
Choose slot A or B, then a fabric. Squares use A; triangles put A in the corner you pick and B in the other half.
Making it for a bed? The quilt size calculator works out blocks and borders for each mattress size.
| Fabric | Cut | Strips across the width | Fabric |
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| Muslin |
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| Indigo |
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| Saffron |
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| Teal |
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Fabric is the length of strips cut across the width, rounded up to the next 1/8 yard or 10 cm. Buy a little extra for straightening the edge and for mistakes.
A small .json file you can keep, share or open on another device.
Saved in this browser only. The block you are working on is also kept automatically.
No saved blocks yet.
Pick a grid size: a 4 × 4 grid on a 12″ block gives 3″ squares, a 6 × 6 grid gives 2″ squares. Choose Square to paint whole squares in fabric A, or Triangle to paint half-square triangles (HSTs): fabric A fills the corner shown in the direction buttons and fabric B the other half. Tap a triangle again to turn it, or use Turn. Pick copies a cell's fabrics into the brush.
Edit any fabric's colour and name, add up to twelve, and remove ones you no longer need. Everything also works from the keyboard: move with the arrow keys and paint with Enter or Space.
The preview repeats your block across the quilt. Block turns rotates every other block, turns each block of a 2 × 2 group a quarter further, or mirrors neighbours, which is how many secondary patterns appear. Sashing adds strips between blocks, with cornerstones where they cross.
For the cutting list, enter the finished block size. Squares are cut at the finished size plus two seam allowances (½″ with ¼″ seams). Triangles are made two at a time from a pair of squares cut 7/8″ larger than the finished size; choose the oversized option to cut 1″ larger and trim each unit to size. Fabric is worked out as strips across the usable width (42″ by default, the width of quilting cotton once the selvages are trimmed).
The Sawtooth Star starter at 12″ finished has 3″ units. Each block needs four 3½″ background squares, four 3½″ centre squares (or one 6½″ square cut as a single piece) and eight HSTs from four pairs of 3 7/8″ squares. Twenty blocks need 80 background squares; twelve fit across a 42″ strip, so you cut seven strips.
From the size of the quilt to the last strip of binding.
Finished size for any bed from drop and pillow tuck, then blocks across and down, sashing and borders.
Square sizes for two, four and eight HSTs at a time, in inches and centimetres, with fabric needed.
Strips to cut across the width of fabric and how much fabric to buy for straight-grain binding.
How many widths to join, which way the seams run and the yardage, with extra for longarm quilting.
Two free tools from outside the quilting room that come in handy when you shop for fabric online.
Fabric shops often ask for an email address before a free pattern download or a welcome discount. A disposable inbox from CleanTempMail needs no sign-up and receives the email straight away, and everything in it is deleted after three days, so the follow-up newsletters never reach your own inbox.
Get a temporary email addressFound a fat-quarter bundle priced well below everywhere else, on a shop you have never heard of? WebTraceCheck can look up the shop's domain and check its security headers, or open the site in a disposable cloud browser that is wiped after the session, before you type in any card details.
Check a shop with WebTraceCheckChoose the Triangle brush, pick fabrics A and B, and choose which corner fabric A should fill with the four direction buttons. Click or tap a square to paint it. Tapping the same triangle again turns it a quarter turn, which is often quicker than changing the direction first.
A plain square needs a 1/4″ seam allowance on each side, so 1/2″ in total. For a half-square triangle, two squares are sewn together along the diagonal and then cut apart, and the diagonal seam takes up extra fabric: with 1/4″ seams the triangle legs must be about 0.854″ longer than the finished size, which quilters round up to 7/8″.
Yes. Tab into the grid, move with the arrow keys and press Enter or Space to paint. R turns a triangle, H switches between the square and triangle brush, O changes the triangle direction, X swaps fabrics A and B, and the number keys choose a fabric. Ctrl+Z and Ctrl+Y undo and redo.
In your browser's local storage on this device. Nothing is uploaded. The current block is kept automatically, and Save block adds it to My blocks. Clearing your browser data removes them, so download a design file for anything you want to keep.
No. It lists one piece per grid square, which always sews together in straight rows. Where several squares of the same fabric sit together, such as the centre of a star, you can cut one larger piece instead: its finished size plus 1/2″.
Each size of piece is cut from strips across the usable width of fabric. The calculator counts how many pieces fit in one strip, how many strips that takes, and adds up the strip widths. It does not include binding, backing, borders or spare fabric for mistakes.