Cut once. Have enough fabric. Every time.
Quarter Inch turns Claude into a quilting friend who never gets the math wrong. Size quilts for any bed, get cut sizes for half-square triangles and flying geese, full cutting charts, yardage for every fabric, and backing, binding and batting in seconds.
Get Quarter Inch Quilt Planner for $15 Calculate my backing
- One-time $15
- Instant email delivery
- 14-day refund
- Works on any Claude plan, even free
Throw quilt: 60 x 72 in, 12 in blocks
12 in blocks with sashing and a border · longarm finishing
Shown with the mathRounded up to 1/8 yd+10% margin
- HSTCut 60 squares at 4-7/8 in4 in finished + 7/8 in · two at a time makes 120Fabric A
- GeeseLarge 9-1/4 in squares, small 4-7/8 in8 x 4 in finished, no-waste 4 at a timeFabric B
- BackBacking: 4-1/2 yd, 2 widths68 x 80 in needed · seam runs the long wayBacking
- BindBinding: 7 strips at 2-1/2 in = 5/8 ydPerimeter 264 + 12 in for cornersBinding
All the quilt math, none of the mistakes
One skill that covers sizing, blocks, cutting, yardage and finishing. Claude picks the right part from what you ask.
Sizes for any bed
Mattress size and drop to finished size, with blocks, sashing and borders that land on it.
Block math
Finished to cut sizes for HSTs (1, 2, 4 or 8 at a time), QSTs, flying geese and setting triangles.
Cutting charts
Strips across the width, then subcuts with counts, fabric by fabric, including precuts.
Yardage for everything
Every fabric, plus backing, binding and batting, rounded up with a sensible margin.
Resizing
Make a pattern bigger or smaller with more blocks, new block sizes or borders, and see the yardage change.
Color and value
Light, medium and dark assigned to each patch, and how to test your fabric pull.
Ask it like you'd ask the quilter at your guild who's good at math
It shows every step, so you can check it before you cut.
Backing: 4-1/2 yd (two widths)
You need 60 + 8 = 68 in by 72 + 8 = 80 in. That's wider than 40 in fabric, so you'll piece it, and each seam uses about 1 in.
- Seam running the long way: 2 widths cover 79 in across (plenty for 68 in). Each is 80 in long: 160 in = 4.44 yd → 4-1/2 yd
- Seam running across: 2 widths cover only 79 in, short of the 80 in length, so you'd need 3 widths of 68 in = 5-3/4 yd. Not worth it.
Binding: 5/8 yd
Perimeter = 2 x (60 + 72) = 264 in, + 12 in for corners and joins = 276 in. At 40 in per strip, that's 7 strips at 2-1/2 in = 17.5 in → 5/8 yd (1/2 yd would leave only half an inch to straighten the cut).
Or use 108 in wide backing: turn it so the 68 in side runs along the length you buy: 68 ÷ 36 = 1.89 → 2 yd, with no seam.
Math you can check
Quarter Inch never just gives you a number. It shows how it got there.
- Working shownEvery cut size and yardage comes with the calculation.
- Sensible roundingCut sizes to the nearest 1/8 in, yardage up to the next 1/8 yd, with a margin.
- Your assumptionsUsable width, seam allowance and finishing method stated up front, and easy to change.
- Respects designersIt helps you resize and calculate for your own use, without copying a pattern's instructions.
Up and running in two minutes
No app to learn and nothing to install on your computer. It lives inside Claude.
Buy once
Pay $15 by card, Apple Pay or Google Pay. Your download link arrives by email in about a minute.
Add it to Claude
Upload the ZIP in Claude under Customize, then Skills. It takes about 30 seconds. No setup, no accounts.
Just ask
"How big should a queen quilt be for a 14 in mattress?" "Cut sizes for 3 in HSTs, 8 at a time." "Yardage for this pattern at twin size."
Start with the free Yardage calculator
A small skill that works out backing, binding and batting for any quilt, plus strips and yards for a set of cut pieces.
- Backing pieced the cheaper way
- Binding strips and yardage
- Math shown, rounded up
Get Quarter Inch Quilt Planner
Pay once, use it on every quilt. Includes the free Yardage calculator too.
How to add it
- Claude on the web or desktop: don't unzip it. Open Customize, then Skills, click +, choose Upload a skill and pick the ZIP. It works on any Claude plan, including the free one: just turn on code execution in Settings, Capabilities.
- Claude Code:
unzip quarter-inch-quilt-planner.zip -d ~/.claude/skills/ - Start a new chat and try: "I want to make a queen quilt with 12 inch blocks. Plan the size, blocks and yardage."
Quarter Inch Quilt Planner
Size, cut, piece and finish with the math done.
$15 one time
- Quilt sizes for any bed or gift
- Block math for every common unit
- Full cutting charts
- Yardage, backing, binding and batting
- Pattern resizing
- Color and value planning
- Updates for a year
Secure checkout by Stripe. Taxes calculated at checkout. 14-day refund.
Prefer to buy on Etsy? Get it on Etsy
New to Claude?
Claude is an AI assistant made by Anthropic, like ChatGPT. Quarter Inch is a skill: a set of expert instructions you add to your own Claude account, so Claude answers like a experienced quilter and pattern writer who knows the craft.
- Make a Claude account at claude.ai. Skills work on every plan, including the free one; paid plans give more usage.
- Turn on code execution in Settings, Capabilities (skills need it).
- Try the free Yardage Calculator skill first. If you like it, the full skill is one purchase.
Not ready for Claude? The free backing and binding calculator on this site works in any browser, no account needed.
Questions
Does it work in metric?
Yes. Tell it you work in centimeters and meters and it does the math in metric, including meter-wide fabrics.
Can it read my pattern?
You can share your pattern's sizes and cutting list and it will recalculate or resize for your own use. It won't reproduce a designer's instructions.
Does it do English paper piecing or foundation paper piecing?
It handles the yardage and layout math for both, and seam allowances for foundation piecing. It doesn't print templates.
What about precuts?
Tell it what you have (jelly rolls, layer cakes, charm packs, fat quarters) and it plans what you can cut from them and what yardage to add.
What do I need to use it?
A Claude account on any plan, including the free one, with code execution turned on (Settings, Capabilities). Free accounts have lower usage limits, so long planning sessions go further on a paid plan. It works in Claude on the web, the desktop app and Claude Code.
What if it doesn't work for me?
Email hello@whatiflabs.ai within 14 days of buying and we'll refund you in full. No forms, no questions.