Frame Size Conversion: Inches to cm

A simple guide to converting picture frame sizes between inches and centimetres — with a full chart of our stocked sizes, the common photo dimensions and the A-series sizes explained.

How do you convert inches to cm? Multiply the measurement in inches by 2.54 to get centimetres (and divide by 2.54 to go from cm back to inches). So a 4 × 6″ photo is 10 × 15 cm, and an 8 × 10″ photo is roughly 20 × 25 cm. Use the chart below to match your artwork to a frame size.

How to convert frame sizes

There are 2.54 centimetres in one inch, so the maths is the same whichever way you go:

Inches to cm: multiply by 2.54 (e.g. 12″ × 2.54 = 30.5 cm).
cm to inches: divide by 2.54 (e.g. 30 cm ÷ 2.54 = 11.8″).

Frame sizes are usually rounded to the nearest neat figure, so a 10 × 12″ frame is sold as 25 × 30 cm rather than the exact 25.4 × 30.5 cm. Always measure your artwork before choosing — our how to measure a picture frame guide walks you through it.

Common photo & print sizes

These are the everyday photo and print sizes we stock, shown in both systems. The imperial size is the traditional name; the metric figure is the rounded equivalent.

Size name	Inches	Centimetres
4 × 6	4 × 6″	10 × 15 cm
5 × 7	5 × 7″	13 × 18 cm
8 × 10	8 × 10″	20 × 25 cm
10 × 12	10 × 12″	25 × 30 cm
11 × 14	11 × 14″	28 × 36 cm
12 × 16	12 × 16″	30 × 41 cm

A-series (A4, A3, A2) sizes

The A-series is a metric paper standard used across the UK and Europe for documents, certificates and art prints. Each size is half the one before it. We stock frames for the three most popular A sizes:

A-series	Centimetres	Millimetres	Inches (approx.)
A4	21 × 29.7 cm	210 × 297 mm	8.3 × 11.7″
A3	29.7 × 42 cm	297 × 420 mm	11.7 × 16.5″
A2	42 × 59.4 cm	420 × 594 mm	16.5 × 23.4″

A4 is not the same as 10×8″. A4 (21 × 29.7 cm) is taller and narrower than a 10×8″ photo (20 × 25 cm) — they are different proportions, so they are not interchangeable. If you have an A4 document, choose an A4 frame; if you have a 10×8″ photo, choose an 8×10 frame.

Large cm frame sizes

For posters, large prints and statement pieces, we also stock these popular metric sizes. They’re sold in centimetres because that’s how larger art and posters are typically described in the UK.

Size name	Centimetres	Inches (approx.)
30 × 40 cm	30 × 40 cm	11.8 × 15.7″
40 × 50 cm	40 × 50 cm	15.7 × 19.7″
50 × 70 cm	50 × 70 cm	19.7 × 27.6″
70 × 100 cm	70 × 100 cm	27.6 × 39.4″

Got an in-between or odd size? If your artwork doesn’t match a size above, you don’t need to compromise — design a made-to-measure frame to any dimension in inches or centimetres.

Frame size conversion FAQs

How do I convert inches to centimetres?

Multiply the measurement in inches by 2.54. For example, 12″ × 2.54 = 30.5 cm. To convert centimetres back to inches, divide by 2.54.

Is 10×8″ the same as A4?

No. A 10×8″ photo measures 25 × 20 cm, while A4 is 21 × 29.7 cm — A4 is taller and narrower. They are different proportions, so a 10×8″ photo will not fit an A4 frame correctly, and vice versa.

Why does the UK use both inches and centimetres for frames?

Traditional photo sizes (4×6″, 5×7″, 8×10″) are long-established in inches, while paper sizes (A4, A3) and larger art prints are metric. Most UK framing uses whichever system is standard for that item, which is why you’ll see both — our chart shows the equivalents side by side.

What if my artwork isn’t a standard size?

You can have a frame made to your exact measurements in either inches or centimetres. Use the frame builder to enter your size and choose your finish, glazing and mount.

Handmade in the UKBy our own framers

Made to your sizeStandard or bespoke

Quality materialsAcrylic glazing & solid backing

Carefully packagedProtected for delivery