Picture frame calculator
Enter your art size and moulding width to get the length of each frame side, measured at the long point of the 45° miter.
Enter your measurements
More options: Room · Extra for cuts and mistakes
- Long sides: cut 2 (long point, decimal)
- 17.125 in
- Short sides: cut 2 (long point, decimal)
- 14.125 in
- Rabbet opening
- 11-1/8 in × 14-1/8 in
- Outside size of frame
- 14-1/8 in × 17-1/8 in
Rabbet: art + 1/8 in clearance = 11-1/8 in × 14-1/8 in
Long point: 14-1/8 in + 2 × 1-1/2 in = 17-1/8 in · 11-1/8 in + 2 × 1-1/2 in = 14-1/8 in
2 × (17-1/8 in + 14-1/8 in) = 62-1/2 in × 1.1 = 68-3/4 in (5 ft 8-3/4 in)
- Long point = the longer, outside edge of a mitered piece. Measure and mark there.
- Net moulding is 62-1/2 in; 68-3/4 in (5 ft 8-3/4 in) adds the allowance for trimming and one bad cut. Each 45° cut on profiled moulding also wastes a triangle roughly the moulding width long.
Quick answers for common sizes
| Example | Answer |
|---|---|
| How much moulding for an 8×10 picture frame | 53-3/8 in (4 ft 5-3/8 in) |
| How much moulding for a 16×20 picture frame | 97-3/8 in (8 ft 1-3/8 in) |
Moulding needed by moulding width (same art size)
| Moulding width (inner lip to outside edge) | Long sides: cut 2 (long point, decimal) | Short sides: cut 2 (long point, decimal) | Moulding to buy |
|---|---|---|---|
| 0.75 in | 15.625 in | 12.625 in | 62-1/8 in (5 ft 2-1/8 in) |
| 1 in | 16.125 in | 13.125 in | 64-3/8 in (5 ft 4-3/8 in) |
| 1.5 in | 17.125 in | 14.125 in | 68-3/4 in (5 ft 8-3/4 in) |
| 2 in | 18.125 in | 15.125 in | 73-1/8 in (6 ft 1-1/8 in) |
| 2.5 in | 19.125 in | 16.125 in | 77-9/16 in (6 ft 5-9/16 in) |
| 3 in | 20.125 in | 17.125 in | 81-15/16 in (6 ft 9-15/16 in) |
Set your miter saw to 45° for every cut. The inside of the rabbet should be a little bigger than the art — about ⅛ in (3 mm) overall — so the glass and backing drop in without binding. New to this? Words explained.
How frame lengths are figured
Picture framers think in terms of the rabbet — the ledge on the back of the moulding that holds the glass, mat and art. The rabbet opening is the art size plus a small clearance. Each side’s long point (outside corner to outside corner) is the rabbet opening plus twice the width of the moulding from rabbet to outer edge.
rabbet opening = art size + clearance long point = rabbet opening + 2 × moulding width moulding to buy = 2 × (long width + long height) + waste rule of thumb: perimeter of art + 8 × moulding width
Example: an 11 × 14 in print with ⅛ in clearance and 1½ in moulding. Rabbet opening 11⅛ × 14⅛ in; cut two sides at 14⅛ in and two at 17⅛ in, long point to long point. That is 62.5 in net, about 69 in (5¾ ft) with 10% extra.
Matting
If you add a mat, size the frame to the mat, not the art. A 2 in mat around an 11 × 14 print makes a 15 × 18 in package; enter that as the art size.
Cutting and gluing tips
- Cut all four sides with a stop block, pairs at a time, so opposite sides are identical — that matters more than the exact length.
- Cut the first miter on each piece, then flip and measure to the long point for the second.
- Check your saw at 45° with a test frame. A 0.5° error shows up as a visible gap at one corner because the four errors add.
- Glue end grain miters with a thin sizing coat of glue first, then reinforce with brads, V-nails or splines.
- Buy moulding in lengths that let you cut a long and a short side from one stick to reduce waste.
Worked examples
Two common sizes are worked through with stick counts and the mistakes that go with them: How much moulding for an 8×10 picture frame and How much moulding for a 16×20 picture frame. The corners are plain 45° miters; for six or eight sides, see What miter angle for a hexagon.
CalculatorMiter Angle Calculator →Making a hexagonal or octagonal frame instead?What you’ll need
- Compound miter sawPremium price
Fast, repeatable crosscuts, miters and bevels for trim, frames and cut lists. A sliding model handles wider boards.
See options on Amazon (opens in a new tab) - Band clamp with cornersBudget price
Pulls all the corners of a frame, hexagon or octagon together at once — the easiest way to glue a mitered ring.
See options on Amazon (opens in a new tab) - Wood glue (PVA)Budget price
Standard yellow glue for joints and panels. Choose a water-resistant type for outdoor projects and check the open time on the label.
See options on Amazon (opens in a new tab) - 25 ft tape measureBudget price
A 25 ft tape with a stiff blade and a readable 1/16 in scale covers everything from cut lists to deck layout.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How much moulding do I need for an 8×10 frame?
About 4½ ft in 1½ in moulding, with extra. Cut lengths are on How much moulding for an 8×10 picture frame.
Do I measure frame sides at the long point or short point?
Framers usually specify the long (outside) point. The short point is the rabbet side, which should be slightly larger than the art.
How much bigger should the frame opening be than the picture?
About ⅛ in (3 mm) larger overall is common — 1/16 in each side — so the glass and art fit without buckling. The visible opening is smaller because the moulding lip overlaps the edges.