# Curtain heading tape calculator

Heading tape is sewn across the flat width of the finished curtain, so the length needed is the cloth in the made-up curtain — the widths bought, less the side hems and the seams at every join — plus a turnback folded under at each end. Hooks are a different measurement entirely: they sit along the curtain once it is gathered, not along the flat tape, which is why counting them on the tape length buys roughly two and a half times too many.

Source: https://fabricmeasure.com/calculators/curtain-heading-tape-calculator/
Last updated: 2026-08-20 (method v1)
Published by FabricMeasure.

---

## The formula

```
flat width per curtain = widths x fabric width - 2 x side hem - joins x 2 x seam
tape per curtain       = flat width per curtain + 2 x turnback
tape in total          = tape per curtain x number of curtains

hooks per curtain      = ceil(GATHERED span per curtain / hook spacing) + 1
```

THE TAPE is measured on the FLAT curtain. THE HOOKS are measured on the GATHERED
curtain. Counting hooks along the tape is the usual error and buys roughly two and
a half times too many.

The flat width comes from the fullness solver, not from a second copy of it, so this
tool and the curtain fullness calculator cannot disagree.

## Defaults

- Turnback per end: 2 cm
- Hook spacing: 8 cm along the gathered curtain
- Side hem: 8 cm per outer edge
- Seam allowance: 1.5 cm

Eyelet and tab-top headings carry NO tape and NO hooks: the fixing is built into the
curtain. Wave tape only works on a wave track. Corded tapes carry three cords.

## Worked example

200 cm track, a pair of pencil-pleat curtains at 2.5x in 140 cm fabric.

| Step | Working | Result |
| --- | --- | --- |
| Tape per curtain | 261 cm of flat curtain + 4 cm turned under at the ends | 265 cm |
| Tape in total | 265 cm × 2 curtains | 530 cm |
| Hooks per curtain | 100 cm of gathered curtain ÷ 8 cm spacing, plus one to finish the run | 14 hooks |

Buy: 5.3 m of tape, 28 hooks.

## Common questions

### How much heading tape do I need for a pair of curtains?

The flat width of both finished curtains, plus a turnback at each end. For a pair made from two widths of 140 cm fabric each, that is a little over 5 metres. It is the flat cloth that matters, not the track width — the tape is sewn on before the curtain is gathered.

### How many curtain hooks do I need?

Count them along the gathered curtain, not along the tape. A pair on a 200 cm track covers 100 cm each once hung, so at 8 cm spacing that is about fourteen hooks per curtain. Counting on the flat tape instead would suggest thirty-four, which is where most over-ordering comes from.

### Do eyelet or tab-top curtains need heading tape?

No. Both have their fixing built into the curtain — an eyelet is a metal ring punched through a stiffened band, a tab is a loop of the same cloth passed over the pole. Neither takes tape and neither takes hooks. A lightweight stiffener behind the band is a separate thing from heading tape.

### Can I use any heading tape on any track?

Almost, with one exception. Wave tape holds a fixed cord spacing that only a wave track is built to carry; on an ordinary track the folds collapse into an uneven gather and the effect is lost. Pencil pleat, pinch pleat and standard tapes all work on a normal track or pole.

### How much cord is in a heading tape?

Three cords run the length of a corded tape and are drawn from one end to gather it, so the cord in the tape is roughly three times its length. You do not buy that separately — it comes in the tape — but it is worth knowing when you are pulling the cords up and wondering how much slack to expect.

## Related tools

- [Curtain fullness calculator](https://fabricmeasure.com/calculators/curtain-fullness-calculator/): How many widths each curtain needs at the fullness you want — and what whole widths really gather to.
- [Curtain fabric calculator](https://fabricmeasure.com/calculators/curtain-fabric-calculator/): Track width, drop, fullness and pattern repeat in; metres or yards to buy out, with every allowance adjustable.
- [Curtain heading types](https://fabricmeasure.com/charts/curtain-heading-types/): Five headings compared on fullness, allowance and what they cost in cloth.
- [Curtain lining calculator](https://fabricmeasure.com/calculators/curtain-lining-calculator/): Lining on its own narrower roll, from the flat width your curtains already need.