Streamer Calculator — Rolls of Streamers Needed

This calculator estimates streamer quantities based on your decoration style. Ceiling drapes, wall streamers and twisted columns scale with your room dimensions; the photo backdrop is a fixed set-piece panel, so its size does not depend on the room.

The formula

Ceiling drapes: Streamers every 30cm across the width, each running the full length of the room. So runs = room width ÷ 0.3, total length = runs × room length.

Wall streamers: Room perimeter — 2 × (length + width) — multiplied by 2.5m (assumed ceiling height) for one vertical drop per metre around the walls.

Twisted columns: One column roughly every 3m around the perimeter (minimum 4), each column about 3m of streamer, then doubled because two streamers are twisted together. So columns = max(4, perimeter ÷ 3), total = columns × 3 × 2.

Photo backdrop: A standard 2m-wide DIY backdrop panel with five streamer drops per metre, each drop about 2m long — 2 × 5 × 2 = 20m before allowance. This is independent of room size.

Each standard roll is taken as 10 metres (25m rolls also exist — check the pack). Your chosen extra allowance — the Waste Factor, 15% by default — covers trimming, twisting and wastage.