How to make a quilt bigger

5 October 2026 · Sashing guides

Plan it in your own fabrics with Sashing →

The quilt we will grow

Every number below starts from one quilt, so you can see what each change is worth: a throw of twenty 12″ blocks, four across and five down, with 2″ sashing between them and one 4″ border. That comes out at 62 × 76″ — the same quilt used in how much fabric for a throw quilt. Its pieced centre, before the border goes on, is 54 × 68″.

Work out what you are aiming for first. A quilt that needs to cover a bed is the mattress plus a drop down each side, and the quilt sizes chart has the common targets and why published charts disagree about them. Knowing you need 76″ rather than “bigger” decides the method for you.

How much does a border add?

A border goes on all four sides, so it adds twice its width to both the width and the length. That is the whole arithmetic, and it is why a border is the fastest way to grow a quilt.

These are the border widths Sashing offers, and it takes up to six borders on one quilt. Six 6″ borders round that 54 × 68″ centre would give 126 × 140″, which tells you the ceiling is not the constraint — taste is.

Borders stack outward, and each one is measured on the quilt with the previous one already attached, so the second border is longer than the first for the same width. Calculating fabric for quilt borders works that through strip by strip.

How wide to go is a judgement, but there is a widely repeated rule of thumb: an outer border between a third and a half of the finished block size. For 12″ blocks that is 4–6″, which several quilting sites give as the range for a block that size (read October 2026). Narrower than that and the border reads as a frame line rather than a border.

Does wider sashing make a quilt bigger?

Yes, but less than people expect, because sashing runs between the blocks and not around the outside. With four blocks across there are only three gaps, so every extra inch of sashing adds 3″ across — and 4″ down, where five blocks give four gaps.

• No sashing: centre 48 × 60″, quilt 56 × 68″ with the 4″ border.
• 2″ sashing: centre 54 × 68″, quilt 62 × 76″.
• 3″ sashing: centre 57 × 72″, quilt 65 × 80″.

3″ is as wide as Sashing's sashing goes, so this method has a hard stop. On this quilt, going from the default 2″ to 3″ buys 3″ of width and 4″ of length; going from no sashing at all to 3″ buys 9″ and 12″. It is still the change worth making when the blocks are busy and want air between them — see how to add sashing to a quilt for the cut sizes and the sewing order. If your pattern has a plain round of fabric outside the blocks as well, that is a border, and it is counted as one here.

Add another row or column of blocks

This is the method that moves a quilt between bed sizes. One more column adds a block plus a sashing strip: at 12″ blocks and 2″ sashing, 12 + 2 = 14″ per column or row.

That last row is exactly Sashing's twin preset. It is also ten more blocks than we started with, which is the honest cost: borders buy inches, blocks buy inches and piecing. If the blocks are the slow part of your quilt, grow the frame instead.

In the app the blocks-across and blocks-down steppers go up to 18 each way, and a new cell arrives as a copy of the last block in its fabrics, so you recolour the new row rather than building it from nothing. Changing the grid also drops the size-preset label, because the quilt is no longer that preset.

Can you scale up the blocks instead?

Sometimes. Sashing draws each block at a fixed list of sizes, because a cut size is only printed where it has been checked, and one size applies to the whole quilt. An Ohio Star is offered at 6, 9 and 12″, so a 12″ Ohio Star throw has nowhere left to scale: the same 4 × 5 grid at 9″ blocks would be 50 × 61″, and at 6″ just 38 × 46″.

Four of the 34 blocks do go above 12″: Bear Paw at 14″, Monkey Wrench at 12½″, Log Cabin at 13¾ and 16½″, and Courthouse Steps at 16½ and 22″. Scaling up changes every cut size in the quilt, which is why the cutting chart is rebuilt rather than scaled — how to read a quilt cutting chart explains what those lines are telling you.

Setting blocks on point

Turning the blocks 45° is the other classic answer, and it is a real one: a 12″ block measures about 16.97″ corner to corner (12 × √2), so the same blocks cover noticeably more quilt, and the setting triangles that fill the edges add more again.

It is worth saying plainly that Sashing does not do it. The app lays blocks out square, and it does not plan on-point settings, setting triangles or corner triangles. If you set your blocks on point, the finished size and the yardage from the app will not match what you sew.

What the extra size costs in fabric

Growing a quilt costs more than the piece you add, because the border, the binding and the backing all grow with it. Adding a 3″ second border to the 62 × 76″ throw, worked the way Sashing plans it on 40″ of usable width:

• The new border: 2 × 76½″ + 2 × (62 + 6 + ½)″ = 290″ of 3″ border. That is eight 3½″ strips, 28″ of fabric, ⅞ yd.
• The binding: the four sides plus the 12″ Sashing adds for corners and the join go from 288″ to 312″, and that is still eight 2½″ strips. No change.
• The backing: 4″ bigger than the top on every side means 76 × 90″ instead of 70 × 84″. Still two lengths seamed down the middle, but 90″ each instead of 84″: 4¾ yd becomes 5 yd.

So 6″ in each direction costs about ⅞ yd of border fabric and a quarter yard more backing. Widening the sashing from 2″ to 3″ instead is cheaper on the frame — the border still takes seven strips and the binding eight — but the 31 sashing pieces go from 2½″ to 3½″ wide, which is 37½″ of background instead of 25″, and the cornerstones go from 2½″ of fabric to 7″. The backing still steps up to 5 yd. Working out quilt backing has the method for any size.

These are Sashing's own rules — ¼″ seams, 40″ of usable width, yardage rounded up to the next ⅛ yard with a ¼ yard minimum — not a published standard. A pattern that plans on 42″, or adds its own safety margin, will quote different amounts.

Which method to pick

• Need a lot of size — add rows and columns, and accept the piecing.
• Need a few inches — one border, or a second one.
• The blocks look crowded — widen the sashing, then border it.
• The quilt is already pieced — a border goes on without unpicking anything you have sewn.

Trying each of them on paper is the slow part. In Sashing, the sashing width, the border widths and the grid are chips and steppers on the Layout panel, and the finished size in the header changes as you tap them, so you can land on a target size before cutting anything. The yardage and the cutting chart behind those numbers are part of Sashing Pro.