How many balloons do I need for a balloon arch?

Multiply the garland length by the fullness in balloons per metre. A lush organic garland runs about 36 balloons per metre, so a 3 metre garland needs roughly 108 balloons. A sparser classic arch uses fewer.

What size balloons should I mix?

Organic garlands look fullest with mixed sizes. A common split is about half at 28 cm (11 inch), 40 percent at 13 cm (5 inch), and 10 percent as 40 cm (16 inch) accent balloons dotted through for depth.

How long does a balloon garland take to build?

Allow roughly one to two hours to inflate and assemble around 100 balloons by hand. More balloons, more colours and a pump versus lung power all change the time, so buy about 10 percent spare for pops.

Balloon Arch Calculator

This balloon arch calculator works out how many balloons you need for a balloon arch or organic garland, and gives you a size mix to buy. You tell it the finished length of the garland and how full you want it in balloons per metre, and it multiplies the two to get a total, then splits that total into large, small and accent balloons in the proportions decorators typically use. An organic garland, the clustered style you see framing doorways and photo backdrops, looks fullest at around 36 balloons per metre when you mix sizes, while a sparser classic arch of single balloons on a frame uses far fewer, so drop the fullness figure if that is the look you are after. The default mix is about half 28 cm (11 inch) balloons, 40 percent 13 cm (5 inch) balloons, and 10 percent 40 cm (16 inch) accent balloons threaded through for depth. Use it to plan a birthday, wedding, baby shower or shop opening without over or under buying. Balloons pop and deflate, so buy roughly 10 percent spare, and remember a garland is heavy once built, so plan how you will fix it to the wall or frame before you start inflating.

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Garland length

metres

Fullness

balloons / m

108

balloons for a full organic garland

Large 28 cm (11 in)54

Small 13 cm (5 in)43

Accent 40 cm (16 in)11

Fullness of about 36 balloons per metre suits a lush organic garland; use 12 to 20 for a lighter classic arch. Buy around 10 percent spare for pops. Estimate only.

How it works

The total is simply the garland length multiplied by the fullness in balloons per metre. That total is then divided into three sizes using the split decorators reach for on organic garlands: roughly half of the balloons at 28 cm, 40 percent at 13 cm, and the remaining 10 percent as larger 40 cm accents that add depth and stop the garland looking flat. The two smaller sizes make up the body of the cluster while the accents sit proud. Rounding keeps the three numbers adding back to the total.

Worked example

You want a 3 metre organic garland at a full 36 balloons per metre. That is 3 times 36, which is 108 balloons. Splitting that mix gives about 54 large balloons at 28 cm (half of 108), 43 small balloons at 13 cm (40 percent), and 11 accent balloons at 40 cm (the remaining 10 percent). Add roughly 10 percent, so around 11 spare, to cover pops while you build, and you would buy about 120 balloons in total.

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