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
Related Calculators
Balloon Calculator
Calculate how many balloons you need for your party venue, including latex, foil and helium options for any celebration. Free online calculator.
Bunting Calculator
Work out how many metres of bunting to buy for your party venue or garden based on the space you want to decorate. Free online calculator.
Streamer Calculator
Estimate how many rolls of streamers and crepe paper you need to decorate your party venue or celebration space. Free online calculator.
Table Decoration Calculator
Plan centrepieces, runners and table decorations for each table at your party or event. Get quantities right first time. Free calculator.
Confetti Calculator
Calculate how much confetti you need for your celebration, wedding send-off or party table scatter based on guest numbers. Free calculator.
Last updated: February 2026
All calculations are estimates. Adjust quantities based on your guests and event type.