Frame size calculator

Frame size is an overloaded phrase. Retail frames are labelled by the opening they hold: an 8×10 frame holds 8×10 artwork or an 8×10 pad of mat and photo. Custom moulding is labelled by the outside dimension you will see on the wall and by the rabbet that hides the glass. This calculator shows both languages so you do not buy the wrong thing.

If you skip a mat, package size equals artwork size. The outside size still grows by roughly twice the moulding face minus the rabbet lip, plus clearance. A 1.5" face is not a 3" add-on to the print; part of that face is covering the glass. People who add 3" to an 8×10 and cut rails to 11×13 are the reason mitre saws get blamed for “bad blades.”

If you add a mat, package size grows first, then the moulding grows around that package. An 11×14 print with 2.5" mats becomes a 16×19 package, which is awkwardly close to 16×20. That is exactly when a standard-size snap is useful. The studio will offer to absorb the leftover into the mat so you can buy 16×20 glass.

ISO sizes sit beside US sizes in the preset list. A4 in a mat looks different from 8×10, and A3 is not 11×14. If you ship prints internationally, calculate in millimetres and keep the unit switch on mm so the workshop cut list does not pass through a fraction conversion at the saw.

Wall scale is the hidden half of frame size. A 24×36 with a fat walnut profile dominates a hallway. The same print in a thin oak face recedes. This calculator gives the rectangle; the studio wall preview places that rectangle on a wall you specify, with an optional eye-level line at 62". Use both if the question is “will this feel huge?”

Multi-frame projects make size discipline mandatory. A gallery of mismatched outsides looks accidental unless you designed it that way. Run each print through this calculator, then add them as separate frames in one project so the workshop can share moulding stock across the set.

Kids’ certificates, concert posters, and jersey frames all abuse the word size. Measure the object, not the memory of the object. Jerseys and textiles need extra depth — that is stack and rabbet, not this page — but the outside width still starts here.

When a result is within 1/2" of 18×24 or 20×30, consider changing the mat rather than building a one-off outside. Glass, acrylic, and backing are cheaper in standard sheets. Custom is for when the artwork is the point, not when you were 6 mm away from a stock size.

The engine never talks to a supplier API. There is no live catalogue of Nielsen or Larson-Juhl SKUs. You type the face width you actually own or plan to buy. That keeps the site honest and offline-friendly.

Open the studio when you need to see the object. Size on a form is a number. Size on a canvas with your photograph inside is a decision.