Work out your mat and frame size
1. What do you need?
2. Units
Your mat cutting plan
- Print size
- 8 × 10 in
- Mat opening (window)
- 7.5 × 9.5 in
- Mat borders
- 2 in all round
- Outer mat = frame size
- 11.5 × 13.5 in
Closest standard frames for this opening
| Frame | Borders it leaves | Fit |
|---|---|---|
| 11×14 in (28×36 cm) | 1.75 in sides · 2.25 in top & bottom | works |
| 12×16 in (30×41 cm) | 2.25 in sides · 3.25 in top & bottom | works |
| 9×12 in (23×30 cm) | 0.75 in sides · 1.25 in top & bottom | tight borders |
The opening is 0.5 in smaller than the print in each direction so the mat can hold it. Check the numbers against your cutter before cutting.
Standard frames and the matted prints they pair with
| Frame | Matted print | Side borders | Top & bottom |
|---|---|---|---|
| 8×10 in (20×25 cm) | 5×7 in | 1.75 in | 1.75 in |
| 11×14 in (28×36 cm) | 8×10 in | 1.75 in | 2.25 in |
| 12×16 in (30×41 cm) | 9×12 in | 1.75 in | 2.25 in |
| 14×18 in (36×46 cm) | 11×14 in | 1.75 in | 2.25 in |
| 16×20 in (41×51 cm) | 12×16 in | 2.25 in | 2.25 in |
| 18×24 in (46×61 cm) | 12×18 in | 3.25 in | 3.25 in |
| 20×24 in (51×61 cm) | 16×20 in | 2.25 in | 2.25 in |
| 24×36 in (61×91 cm) | 20×30 in | 2.25 in | 3.25 in |
Only the sizes you type are used, and only in this browser. No photo, filename or account is requested; entered sizes are not saved or sent in analytics.
Prefer frameless? Browse gallery-wrapped canvas portraits →Mat opening, outer size and overlap — the three numbers that matter
A picture mat has two sizes, and mixing them up is the classic framing mistake. The opening (the window) must be cut smaller than the print, because the mat needs a lip — the overlap, conventionally ¼ inch per edge — to hold the print behind it. The outer edge of the mat must equal the frame’s glass size exactly. This calculator does that double subtraction for you: print size minus overlap gives the opening, opening plus your chosen border gives the outer mat, and the outer mat is the frame size to buy.
Bottom-weighting is the professional touch most first mats miss: a window centered by pure math looks like it is sliding down the mat, so framers cut the bottom border ⅜–¾ inch deeper than the other three. Turn on the bottom-weighting option and the outer size and cutting plan update honestly — including the note that a bottom-weighted window is a custom cut, not something a pre-cut standard mat provides.
Custom cut or standard frame — both answers at once
Every calculation returns the exact custom numbers and the three nearest standard frames with the borders each would leave, flagged when a border falls under an inch and starts to look pinched. That means one pass answers both workflows: take the exact outer size to a mat cutter or custom framer, or pick the standard frame whose borders you can live with. The reverse mode does the same arithmetic backwards for a frame you already own.
This page only does mat and frame arithmetic. If the question is which shape your photo crops to, that belongs to the photo aspect ratio calculator; whether the pixels can print sharply, to the canvas size calculator; which artwork size suits the room, to the portrait size guide; and where the nail goes, to the picture hanging height calculator. PortraitGift’s own canvases arrive gallery-wrapped — no mat or frame required — which is exactly why this calculator can be honest about what framing a paper print really takes.
How it works
- Choose “Mat for my print” or “Fit print to a frame”, and inches or centimetres — no photo, filename or account is requested.
- Enter the print size and the border you want (or your frame’s glass size), plus the optional overlap and bottom-weighting.
- Read the exact opening, outer mat and frame size — or the borders your frame leaves — then copy the cutting plan.
Frequently asked questions
What size mat do I need for an 8×10 print?
With the standard ¼-inch overlap the mat opening is 7.5 × 9.5 inches. In the classic 11×14 frame that leaves 1.75-inch side borders and 2.25-inch top and bottom borders; a 16×20 frame turns the same print into a dramatic wide-matted piece with 4.25-inch and 5.25-inch borders.
Why is the mat opening smaller than my print?
The mat must overlap the print’s edges to hold it — otherwise the print would fall through the window. A ¼-inch (0.6 cm) lip per edge is the framing standard, which is why an 8×10 print gets a 7.5 × 9.5 opening. The overlap field lets you change that default.
What is bottom weighting on a picture mat?
Cutting the bottom border slightly deeper — usually ⅜ to ¾ inch — than the other three. A mathematically centered window reads as if the picture is sagging; the deeper bottom border corrects the optical illusion. It is a custom cut: pre-cut standard mats are centered.
What size frame do I need for a matted print?
The frame’s glass size must equal the mat’s outer size: opening plus twice the border. The reference table on this page shows the classic pairings — an 8×10 print traditionally sits in an 11×14 frame, an 11×14 in a 14×18, and a 16×20 in a 20×24.
Does this calculator upload or store anything?
No. It accepts size numbers only, performs the mat arithmetic in your browser, and never requests a photo, filename or account. The sizes you enter are not saved and are not included in analytics.
Prefer no frame at all? Explore gallery-wrapped canvas portraits →