Garland length calculator: how much garland for a staircase

How much garland for a staircase banister

Retailers’ rules of thumb multiply the length of the rail. Matt Bowman, founder of Tradition Company, told Martha Stewart’s garland guide to allow 1.5 to 2 feet of garland for every linear foot of stairs, draped 1 to 2 feet below the railing. The Christmas Loft suggests about 1.5 feet per foot of banister. Both are starting points: the real answer depends on how many swags you make and how deep they hang, and that is what the calculator measures.

Measure the rail along its slope, from the newel post at the bottom to the last tie point at the top, and the height it climbs. Decide where you will tie the garland (every few balusters, or at each bow) and how far each swag should drop.

How the swags are measured

A garland hanging between two tie points takes the shape of a catenary, the curve of any rope or chain hanging under its own weight. For a swag of span x between ties at the same height, sagging d at the middle, the curve is y = a·cosh(x ÷ a), where a is found from the sag, and its length is 2a·sinh(span ÷ 2a). On a stair rail the two ties are at different heights, so the calculator solves the sloping case too: it fits the catenary through both tie points with your sag measured straight down from the rail, and adds up the swags. The tests behind this page check it against an independent numerical solution.

For shallow swags the everyday shortcut, span + 8 × sag² ÷ (3 × span), is close: a 4 ft swag hanging 1 ft deep is 4.60 ft as a catenary and 4.67 ft by the shortcut. For deep swags it overshoots; a 2 ft swag hanging 1 ft deep is 2.99 ft, not 3.33 ft. Thick, stiff garland does not hang quite like a rope, so allow a few inches extra per swag and buy whole lengths, rounding up.

Mantel, doorway and tree

• Mantel. Balsam Hill says to allow at least four feet more than the mantel; the Martha Stewart guide gives 1.5 to 2 times the mantel’s length. A 5 ft shelf with three 6 inch swags and 2 ft hanging at each end takes 10 ft.
• Doorway. Up one side, across the top and down the other: twice the height plus the width. A 36 × 80 inch door frame takes 16 ft 4 in; Matt Bowman’s team usually uses about 24 ft for a front door, cut into two pieces.
• Tree. A spiral round the outline of the tree is the same cone geometry as the lights calculator. Five rounds on a 7 ft tree 4.2 ft wide take 34 ft; the guide’s 9 to 12 feet of garland per foot of tree, 63 to 84 ft here, works out to rounds every 7 to 9 inches, tucked into the branches.

How much ribbon for bows and for the tree

There is no standard bow, so the calculator counts yours. Each loop of a bow uses twice its length of ribbon (out and back to the knot), then come two tails and a short piece to wrap the centre, for which it allows 3 inches. A six-loop bow with 4 inch loops and 10 inch tails takes 71 inches, about 2 yards (1.8 m); six of them take 11.8 yards, two 10 yard rolls.

On the tree, ribbon goes on in a spiral or in cascades from the top down. A spiral uses the cone formula; a cascade is the slant height of the tree, from the tip to the bottom edge. Add an allowance for tucking it into the branches, 20% to start. King of Christmas puts a standard-sized tree at about 10 to 20 yards of ribbon, a useful check: five cascades on a 7 ft tree come to about 14.6 yards with 20% tuck.

Common mistakes

• Measuring the stairs instead of the rail. The rail along the slope is longer than the run of the steps.
• Forgetting the tails. A bow at each end with a foot of garland hanging down adds two feet.
• Buying exactly the number. Garland comes in fixed lengths, and pieces need to overlap where they join.
• Wiring garland lights without checking the plug. Pre-lit garland counts towards the same end-to-end limits as tree lights.

Making your own bows or wreath decorations? Craft Mirth has calculators for candles, resin and party crafts.