PartyCalcs.uk
Banner Calculator — Party Banner Sizes & Quantities
Work out banner sizes and quantities needed for your party or event venue.
How We Calculate This
This calculator estimates banner quantities based on message length and the number of display locations.
The formula
Banner length = number of characters x 15cm per character
One banner is needed per location. Letter banners are assembled from individual flags, typically 15cm wide each, so for that type the calculator also tells you how many letter flags to buy; custom printed and fabric banners are a single finished piece per location, so no flag count is shown. Enter your wall width (optional) and we will check the banner fits and show the spare space each side.
Frequently Asked Questions
A standard letter banner with HAPPY BIRTHDAY is about 2 metres long. For custom messages, allow about 15cm per letter. Measure your wall space first to ensure the banner fits without looking cramped.
The most popular spot is above the main table or buffet area. Other good locations include the entrance, above the cake table, and on the wall behind the dance floor. Make sure banners are at eye level or above.
Letter banners are cheapest and most versatile. Custom printed banners look more professional for milestone birthdays or themed parties. Fabric banners are pricier but reusable and look premium.
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Last updated: February 2026
All calculations are estimates. Adjust quantities based on your guests and event type.