PencilCADSketch
Pen, marker, pencil, highlighter, eraser, lasso and a ruler, on six kinds of paper. Drag the ink swatch onto a closed shape to shade it.
PencilCAD · 2D CAD for Apple Pencil
Sketch it like paper. Dimension it like CAD.
Lines snap to isometric or grid paper and weld at the corners. Every dimension shows its real length. Write a number with your Pencil and the line takes that size. When it’s ready, export a PDF, SVG or DXF to scale.
Two toolbars, one pad
Scratch paper when you’re thinking. CAD when it counts.
Pick Sketch or CAD in Settings and the toolbar changes to suit. Pages look the same either way, so a doodle can grow into a drawing you build from.
CAD
Select, Line, Measure, Shape, Modify, Constrain, Text and Layers, with the pen and eraser for notes. Every line, box, circle and arc stays editable.
Pencil-first constraints
Write the number. The drawing follows.
Other apps make you tap a line, find a menu and type. In PencilCAD you write 60 beside it. Numbers become driving dimensions, and the marks you learned in geometry class become constraints.
- 3D printing
- Woodworking
- CAD prep
- Laser cutting
- DIY projects
Write a size, get a dimension.
In the Constrain tool, write 120, 3 1/2, 2′6″, R20 or ⌀40 beside a line, arc or circle. It becomes a driving dimension and the shape resizes to match. Write 45° between two lines to set their angle. Your handwriting is read on the iPad, offline.
Draw the marks from school geometry.
Tick two lines and they’re equal. Arrows make them parallel, a corner box makes them square, and a loop around two ends joins them. A mark the app isn’t sure about is never guessed.
Hold a scribble to make it CAD.
Draw a rough shape with the CAD pen and keep the Pencil still for a moment at the end. It becomes welded lines, arcs or a circle, straightened by the constraints it implies.
Fully defined, in one tap.
Finish adds the sizes and constraints a sketch is missing, at the sizes it has now, so nothing moves. Press a point to see how it can still move, and fully defined sketches turn green in the Constrain tool.
A clash comes with a fix.
When a new size or constraint fights one you already have, PencilCAD names the one in the way and offers to replace it in a single undo step, instead of just saying no.
CAD tools
Real drafting tools, made for touch.
Lines, boxes, circles, ellipses, arcs and curves all stay editable. Drag a corner and everything joined to it follows.
Snaps that know what you mean.
Lines land on the grid, on ends, midpoints, centres and crossings, or run tangent, square or parallel to what’s there, with a cue that says which. Ends weld onto corners with a ring to show it. On a keyboard, type 80,40 mid-drag for an exact size.
Dimensions in your units.
Millimetres, centimetres, metres, inches to 1/32, or feet and inches. Set the page’s scale once and every dimension relabels. Radius and diameter dimensions and text labels cover holes, fillets and part names.
Trim, fillet, offset, array.
Modify trims back to crossings, extends, fillets, chamfers and offsets. Select several shapes to move, copy, rotate, mirror, scale or array them, and keep construction lines on a layer of their own.
Import and export
From a photo to a DXF, at true size.
Trace over a photo, a scan or a PDF plan. Bring in DXF and SVG files as shapes you can edit. Then send the drawing to Fusion, Onshape, Shapr3D or a printer at the scale you drew it.
Export to scale.
PDF fits one Letter or A4 sheet at a standard scale, with a check bar you can measure with a ruler. SVG comes out in millimetres or inches, and DXF with layers and colours, so a 16-inch line opens as 16 inches.
Trace a photo or a PDF.
Import from Photos, the document scanner or Files, or drop a picture on the page. It sits under the drawing on a locked layer. Tap two points, give the length between them, and it’s to scale.
DXF and SVG come in editable.
Lines, arcs, circles, ellipses, splines and text arrive as PencilCAD shapes at true size, with units read from the file and touching ends joined, ready to trim, dimension and constrain.
Still scratch paper
Everything a pad of paper does. Nothing it doesn’t.
No documents, no saving, no setup. PencilCAD opens to the page you left and keeps up with your Pencil.
Just write.
Pick up your Pencil and go. The page is already there, and it’s saved as you draw.
Swipe for a fresh page.
Two fingers across the page turn to the next sheet. Pull past the last one for a new sheet. A pad holds up to 50.
Tear it out.
Done with a page? Hold two fingers on it and it tears off the pad. Changed your mind? Tap Undo on the page pill and it’s back.
Shade the faces.
With the Sketch tools, drag the ink swatch off the toolbar onto any closed face and it fills right up to your lines, even with a tiny gap at a corner. Three tones and a box reads as solid.
Pick your paper.
Isometric, dot grid, grid, lined, calligraphy or blank, in three sizes, on warm paper or a dark chalkboard that’s easy on the eyes at night. Each page is twice the screen each way, and you can zoom from the whole page to 8×.
iCloud and iPhone
Draw on the iPad. Check it on your phone.
Pages sync through your own iCloud. On iPhone, PencilCAD is a viewer, so the sizes come with you to the lumber yard or the shop floor.
- Syncs on its own, page by page
- Works offline and catches up later
- Pan, zoom and share on the iPhone
Private by design
Your pages stay yours.
Your drawings are your work. They shouldn’t need an account, and nobody else should see them.
Read the privacy policy →-
No account.Nothing to sign up for, nothing to log in to.
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Your iCloud, not our servers.Pages sync through your private iCloud database. We never see them, and handwriting is read on the iPad.
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Anonymous stats, your call.Feature counts and crash reports help us improve. One switch in Settings turns them off.
Pricing
$6.99. Once.
Every tool on this page, on your iPad, with the viewer on your iPhone. No subscription, no in-app purchases, no account.
- Sketch and CAD toolbars
- Pencil-first constraints
- PDF, SVG and DXF export to scale
- Photo, PDF, DXF and SVG import
- iCloud sync and the iPhone viewer
- Up to 50 pages, saved as you draw
Needs iPadOS 17 or later. Made for Apple Pencil. See every feature →
Questions
Sketching and CAD on iPad, answered.
What is isometric paper used for?
Drawing objects in 3D without perspective. Its lines run vertically and diagonally both ways, so a box’s three visible faces line up with the grid and parallel edges stay parallel. Engineers, woodworkers, makers and game artists use it to sketch parts, joints and layouts. In PencilCAD it’s one of six paper types, and lines, shapes and dimensions snap to it.
How do you dimension an isometric drawing?
Run each dimension parallel to the edge it measures, in the plane of that face. Witness lines carry the edge out past the part, the dimension line runs between them with a tick or arrowhead at each end, and the size is written along it. In PencilCAD, pick Measure and drag from one corner to the other: it draws the dimension along the edge with witness ticks and angled end marks, and labels it with the length in your units. The full guide has a worked example.
What is the best app for isometric drawing on iPad?
It depends on how finished the drawing needs to be. For a 3D model you’ll manufacture from, use a CAD app such as Shapr3D or Onshape. For the sketches you’d otherwise do on graph paper, look for isometric paper, lines that snap to it and dimensions that show real lengths. That’s what PencilCAD is built for, with constraints when the sizes must be exact, and nothing to name, file or sign in to.
Can I sketch woodworking plans on an iPad?
Yes. Sketch the piece on isometric paper and dimension it in inches, down to 1/32, or in feet and inches. Give each part or joint its own page: a pad holds up to 50. Grid paper suits flat views and cut lists, and a PDF export prints at a true scale for the shop.
Can you do CAD on an iPad, and where does sketching fit?
Yes. Full 3D CAD apps such as Shapr3D and Onshape run on iPad. A 2D sketch still comes first for most parts, because working out the shape and the key sizes is faster with a pencil. PencilCAD covers that step, then exports a DXF or SVG at true size, so the sketch becomes the start of your model.
Can PencilCAD export DXF for Fusion 360?
Yes. Share a page as DXF, with layers and colours, or as SVG in millimetres or inches, and it opens at the size you drew it in Fusion, Onshape, Shapr3D, Inkscape or laser-cutter software. A PDF export prints to scale on Letter or A4, with a check bar to measure.
Is PencilCAD a subscription?
No. PencilCAD is $6.99 once on the App Store. There’s no subscription, no in-app purchase and no account to make.
Does PencilCAD work on iPhone?
Yes, as a viewer. Pages you draw on the iPad sync through your iCloud, and the iPhone app shows them to pan, zoom and share, so the sizes come with you to the shop or the lumber yard. Drawing and editing happen on the iPad.
Grab a fresh sheet.
Sketch the next part with PencilCAD, on the App Store for iPad.