What Size Is an A3 Frame?
A3 frame dimensions and how to choose frames for A3 posters and prints.
Exact dimensions
Quick answer
A3 is 297mm x 420mm. Or approximately 11.7 x 16.5 inches. A mounted A3 frame is typically 40x50cm or larger externally. A3 is a common size for art prints, posters, and photography.
Common uses
A mounted A3 frame is typically 40x50cm or larger externally. This is one of the most commonly used sizes in the UK for both personal and business purposes. Understanding the exact dimensions helps you choose the right packaging, frame, or postage rate.
Need to know about postage? Check stamp prices or large letter stamp costs.
Postage information
A3 is a common size for art prints, posters, and photography. Always check the thickness and weight of your item as well as the dimensions. Items that exceed standard letter limits (240mm x 165mm x 5mm, 100g) need large letter postage. Items exceeding large letter limits (353mm x 250mm x 25mm, 750g) go as small parcels.
Envelopes and mailers in every size
C5, C6, DL, and custom sizes available. Quality envelopes for personal and business post.
Browse envelopesFrequently asked questions
A3 is 297mm x 420mm. Or approximately 11.7 x 16.5 inches.
A3 is a common size for art prints, posters, and photography. Check Royal Mail size and weight limits for the correct rate.
Post Offices, stationery shops, supermarkets, and online retailers like ProcuraPack stock common envelope and stationery sizes.
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