Easy Wood Calc

How much moulding for a 16×20 picture frame?

Short answer

A 16 × 20 in print in 2 in wide moulding needs about 97.4 inches of moulding, 10% extra included. Cut 2 @ 24-1/8 in, 2 @ 20-1/8 in, long point to long point, and buy 2 sticks of 8 ft — one is not quite enough once each miter’s offcut is counted.

How to work it out

  1. Rabbet: art + 1/8 in clearance = 16-1/8 in × 20-1/8 in
  2. Long point: 20-1/8 in + 2 × 2 in = 24-1/8 in · 16-1/8 in + 2 × 2 in = 20-1/8 in
  3. 2 × (24-1/8 in + 20-1/8 in) = 88-1/2 in × 1.1 = 97-3/8 in (8 ft 1-3/8 in)

At 16×20 the frame starts carrying real weight: a sheet of glass this size, a mat and backing all hang from four glued miters. A wider, deeper moulding such as the 2 in profile used here is a sensible minimum.

Adjust for your project

in
in
in
Each side; the frame is sized to the mat
in
Lay the moulding face down and measure from the step the glass sits in (the rabbet) to the outer edge.
ft
The length the shop sells it in
More options: Room · Extra for cuts and mistakes
in
Added to the art size each way — 1/8 in lets the glass and backing drop in.
%
Cut 4 pieces (long point, 45°)2 @ 24-1/8 in, 2 @ 20-1/8 in
Moulding sticks to buy2 sticks
Moulding to buy97-3/8 in (8 ft 1-3/8 in)8.11 ft
Long sides: cut 2 (long point, decimal)
24.125 in
Short sides: cut 2 (long point, decimal)
20.125 in
Rabbet opening
16-1/8 in × 20-1/8 in
Outside size of frame
20-1/8 in × 24-1/8 in
  • Long point = the longer, outside edge of a mitered piece. Measure and mark there.
  • Net moulding is 88-1/2 in; 97-3/8 in (8 ft 1-3/8 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.

For this job · affiliate link
Band clamp with cornersOn a frame this size, a band clamp with corner blocks squeezes all four miters evenly — much easier than juggling four corner clamps.
View on Amazon (opens in a new tab)

16×20 frame: sticks to buy by stick length

16×20 frame: sticks to buy by stick length
Stick lengthMoulding sticks to buy
6 ft2 sticks
8 ft2 sticks
10 ft1 stick
12 ft1 stick

What to know about a 16×20 frame

The trap is the stick count. The net perimeter is 88-1/2 in, which looks as if it fits in one 8 ft stick, but each side also needs an offcut about as long as the moulding is wide plus a saw kerf, and that pushes the total to roughly 97 in. Buy two 8 ft sticks, or one 10 ft stick if your supplier has it.

Reinforce the corners. Glue alone on end-grain miters is weak at this size; add V-nails from the back, brads through the sides, or splines across the corners. A band clamp with corner blocks holds all four joints square while the glue sets.

Think about the glazing. Glass is heavy and fragile at 16 × 20 in, and many framers use acrylic for large frames that hang over furniture or in children’s rooms. Hang the finished frame on two D-rings or a wire rated well above its weight, fixed into the side rails rather than the corners.

A popular combination is a 16×20 frame with a mat cut for an 11×14 print. In that case the frame is still 16×20, so these cut lengths do not change — only the mat opening does.

For a small first frame to practise on, How much moulding for an 8×10 picture frame uses a single stick.

Different size? Use the full Picture Frame Calculator.

What you’ll need

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

Should a 16×20 frame use glass or acrylic?

Either works. Acrylic is lighter and will not shatter, which suits large frames and busy rooms; glass scratches less and is cheaper. Check that the rabbet is deep enough for the glazing, mat and backing together.

Will one 10 ft stick of moulding make a 16×20 frame?

Yes — 1 stick of 10 ft covers all four sides of 2 in moulding with their offcuts: 2 @ 24-1/8 in, 2 @ 20-1/8 in.

How much 3 in wide moulding for a 16×20 frame?

About 106.2 inches with 10% extra. Cut 2 @ 26-1/8 in, 2 @ 22-1/8 in, long point to long point — that takes 2 sticks of 8 ft.

How much moulding for a 16×20 print with a 2 in mat?

About 115 inches. The frame grows to fit the 20 × 24 in mat: cut 2 @ 28-1/8 in, 2 @ 24-1/8 in.

Other common sizes