---
title: "Buttonhole Spacing Calculator & Marking Guide | Seam & Story"
description: "Space buttons evenly between the first and last, keep one at the bust line, size each buttonhole and print a true-scale marking guide."
url: https://seamandstory.cfd/buttonhole-spacing-calculator/
---

Pattern piece D

# Buttonhole spacing calculator

Even spacing from the first button to the last, an optional button fixed at the bust line, the buttonhole length for your buttons, and a marking guide that prints at true size.

## How to space buttons and buttonholes

Measure the opening from its top edge (the neckline or the top of the band) to its bottom edge, then decide where the first and last buttons go. The calculator divides the distance between them by one less than the number of buttons, because that is the number of gaps. Choose **Spacing** instead to say roughly how far apart you want them; it rounds to the nearest whole number of buttons and spaces them exactly.

On a blouse or dress, a button at the fullest part of the bust stops the front from gaping. Tick **Keep a button at a fixed point** and the gaps above and below that point are shared out so they come out as nearly equal as possible.

**Buttonhole length** is the diameter plus ⅛ in (3 mm). For domed, thick or shank buttons, wrap a strip of paper round the widest part, measure it and type it in the circumference box: half the circumference plus ⅛ in is used instead. Make a test buttonhole on a scrap of the same layers first.

**Placement**: the buttons sit on the centre front line. Horizontal buttonholes start ⅛ in past centre front toward the edge, because the button rests at that end. Vertical buttonholes run along centre front; here they start ⅛ in above the button mark so the button sits at the top. The extension from centre front to the finished edge is shown equal to the button diameter.

Worked example: a 26 in opening, first button 1 in from the top, last 5 in from the bottom, 7 buttons: the buttons run from 1 in to 21 in, 3⅓ in apart. With a fixed button at 9 in they split into gaps of 4 in above and 3 in below.

**Print marking guide** prints strips at true size, split across pages with a 1 in and 2 cm bar on each to check the scale; set the print size to 100%.

## Sources

- American Sewing Guild, [Button and buttonhole positioning](https://www.asg.org/button-and-buttonhole-positioning/): divide the distance by one less than the number of buttons; buttonholes ⅛ in longer than the button; horizontal holes start ⅛ in from centre front toward the edge; vertical holes on centre front.
- New Mexico State University, [Machine Buttonholes Made Easy](https://pubs.nmsu.edu/_c/C231/) (Guide C-231): half the circumference plus ⅛ in for a test buttonhole; horizontal holes extend ⅛ in over centre front; a buttonhole at the bra line; 2 to 3½ in apart is standard.
- Sewing & Craft Alliance, [The relationship between button size and buttonhole placement](https://www.sewing.org/html/learn-to-sew-button-size-butto.html): buttons at centre front, and an extension equal to the button's diameter.

## Questions

**Should the first button be at the very top?**

Not quite: it needs room for its buttonhole and a little fabric above that, so use the pattern's mark if it has one. On a shirt with a collar stand, the top button goes on the stand and is spaced separately; enter the first button on the front band here.

**Horizontal or vertical buttonholes?**

Horizontal buttonholes take strain across the body well, so they suit fitted fronts and waistbands. Vertical ones suit narrow plackets and bands, where a horizontal hole would not fit, and let the button move up and down a little.

**I lengthened the pattern. How do I respace the buttons?**

Enter the new opening length and keep the first and last distances the pattern used. Keep the same number of buttons and they spread out evenly, or switch to Spacing to keep the gaps close to the original and add a button.

**Why is my buttonhole longer than the button?**

A button has thickness as well as width, so a hole exactly as long as the diameter is a struggle to fasten. The extra ⅛ in, or the half-circumference rule for domed buttons, gives it room to pass through.