How to Make Perfect Half-Square Triangles (HSTs) — Free Quilter’s Guide

If you’ve ever struggled with half-square triangles (HSTs) that don’t line up or feel frustrated by mismatched seams, you’re not alone! Accurate HSTs are the foundation of so many beautiful quilt blocks — and once you master them, your piecing becomes faster, cleaner, and so much more enjoyable.

Even if you already know the basic HST techniques, it’s easy to forget the formulas, sizing adjustments, or when to trim… and really, you don’t have to memorize this!
That’s why I created a clear, practical guide — your go-to reference for making perfectly sized HSTs every single time.

💡 What You’ll Learn in the HST Guide

This guide walks you through three essential techniques for making HSTs:

✂️ 1. HSTs 2 at a Time — simple and reliable for scrappy quilts or small projects.

⚡ 2. HSTs 4 at a Time — efficient and consistent when you need matching units.

Here is what I made with this technique and some charm squares (two-color pinwheels):

🚀 3. HSTs 8 at a Time — the fastest way to mass-produce identical HSTs for large quilts.

This is one of my favorite quilt blocks that features HSTs — and yes, it takes more than 8 of them!

Each technique includes clear formulas, step-by-step instructions, and printable sizing charts, so you can confidently choose the technique that fits your project and sewing style.

🎯 Why Accurate HSTs Matter

When your HSTs are the right size with crisp corners and clean edges, your blocks fit together beautifully — saving you time and frustration.
Whether you love precise piecing or prefer quick results, this guide shows you how to balance speed with accuracy, so quilting feels joyful, not stressful.