- Size 10 is the finer, bedspread-weight thread for lace, doilies, tablecloths and snowflakes.
- Size 3 is heavier, works up faster and, per the maker, drapes beautifully for shawls and accessories.
- Size 10 is labeled for 1.6 to 2.25 mm hooks; size 3 pairs with a larger hook.
- Size 10 yardage is printed by color: 400, 350 or 300 yards per ball.
- New to thread? Start with size 3, then step down to size 10.
Size 10 vs size 3 comes down to one thing: thickness. In thread sizing, a lower number means a thicker thread, so size 3 is noticeably heavier than size 10 and makes bigger, bolder stitches.
Aunt Lydia's sells both in mercerized cotton. To keep the comparison fair, we set the Classic 10 Black three-pack against the size 3 Black two-pack, then cover hooks, yardage, drape and the projects each weight suits best.
Aunt Lydia’s Classic 10 Cotton Crochet Thread
Aunt Lydia's Crochet Thread - Size 3 - (2-Pack) Black
Size 10 vs size 3 at a glance
| Feature | Classic 10 (size 10) | Size 3 |
|---|---|---|
| Thickness | Finer | Heavier |
| Weight label | 3-ply bedspread weight | ~ Heavier thread weight |
| Fiber | 100% mercerized cotton | Mercerized cotton |
| Hook | 1.6 to 2.25 mm (US 6, 7, 8, B-1) | ~ Larger hook; see the ball band |
| Yardage | 400 / 350 / 300 yd by color group | ~ Not printed on these listings |
| Work speed | Slower, more detail | ✓ Faster, per the maker |
| Drape | Crisp, holds starch | ✓ Drapes well for shawls |
| Pack in this comparison | 3 balls | 2 balls |
Aunt Lydia’s Classic 10 Cotton Crochet Thread
Check price →Aunt Lydia's Crochet Thread - Size 3 - (2-Pack) Black
Check price →Both picks are black so color does not skew the choice. Every other color and pack is in the full Aunt Lydia's comparison table.
What is the difference between size 10 and size 3 thread?
Thread is numbered the opposite way to yarn weights: the higher the number, the finer the thread. Size 10 is the classic middle weight of thread crochet. Size 3 sits on the heavy end and behaves a little more like a fine yarn.
Size 10: detail and structure
Aunt Lydia's Classic 10 is 100% mercerized cotton in a 3-ply bedspread weight. The listing gives a gauge of 32 to 42 double crochet over 4 inches. That many stitches in a small space is what lets lace look like lace. It also stiffens well with starch, so doilies, snowflakes and stand-up edgings hold their shape.
Size 3: speed and drape
The maker describes its size 3 as a lustrous thread that drapes beautifully for shawls and accessories, and says it is thicker and works up faster than smaller size threads. The two-packs on this site come in black, sage and warm teal.
Aunt Lydia's Crochet Thread - Size 3 - (2-Pack) Sage
Check price →
Aunt Lydia's Crochet Thread - Size 3 - 2 Pack Warm Teal
Check price →
Aunt Lydia’s Classic 10 Cotton Crochet Thread
Check price →Yardage and how far each thread goes
Size 10 yardage is printed clearly by color group. The size 3 listings on this site do not print yardage, so check the ball band before you plan a large piece.
Classic 10 yards per ball
Size 10 only; per the Classic 10 listing
Because size 3 is thicker, a project of the same dimensions uses more yards of size 3 than of size 10. In exchange, you finish sooner and the fabric is heavier.
A practical approach is to buy by the finished piece rather than by the ball. For size 10, divide the yardage in your pattern by the ball size for your color group and round up. For size 3, read the yardage on the band of the first ball you buy, then order the rest in one go so the dye lot matches. Either way, a spare ball costs less stress than a mismatched last round.
How to choose: size 10 vs size 3 by project
| Project | Size 10 | Size 3 |
|---|---|---|
| Traditional doily | ✓ Best fit | ~ Larger, bolder doily |
| Tablecloth or bedspread | ✓ Bedspread weight | ✗ Heavy and slow to finish |
| Snowflakes and ornaments | ✓ Crisp points | ~ Chunkier flakes |
| Shawl or wrap | ~ Very fine and slow | ✓ Drapes well, per the maker |
| Bag trim or table runner border | ~ Delicate | ✓ Reads from a distance |
| First thread project | ~ Takes patience | ✓ Easier to see and handle |
- Start from the pattern. If it names a thread size, use it; gauge and final size depend on it.
- Think about distance. Size 3 edgings read from across a room; size 10 rewards a close look.
- Think about time. Size 3 works up faster for gifts on a deadline.
- Think about your eyes and hands. The finer the thread, the smaller the hook.
If you are deciding as a beginner, our crochet thread for beginners guide lays out a size 3 to size 10 path.
Can you substitute one for the other?
You can, but the piece will change. Working a size 10 pattern in size 3 with a larger hook makes a much bigger finished item, which can be a happy result for a doily that becomes a table topper. Going the other way shrinks the piece and makes it more delicate. Stitch counts stay the same either way; only the scale changes. That is why the size 10 vs size 3 question matters most for fitted items such as collars, bag flaps or a runner made for one specific table, where the finished measurement has to be right.
For more size 10 options, see our best size 10 crochet thread list, the Classic 10 review and our doily thread guide. Bulk buyers should read the Jumbo review.
Aunt Lydia’s Classic 10 Cotton Crochet Thread
Check price →In the size 10 vs size 3 choice, size 10 wins for fine lace, doilies, tablecloths, bedspreads and snowflakes: it is the bedspread-weight thread with clearly printed yardage and a 1.6 to 2.25 mm hook range. Size 3 wins for speed, drape and bold edgings that need to be seen from a distance, and it is the friendlier first step for crocheters coming from yarn. Pick by project, not by habit.
FAQ
Size 10 vs size 3: which is thicker?
Size 3 is thicker. In crochet thread, a lower number means a heavier thread.
What hook do I use for size 3 thread?
A larger hook than for size 10. Check the ball band and your pattern for the exact size; the size 3 listings here do not print one.
Is size 10 or size 3 better for doilies?
Size 10 is the traditional doily weight. Size 3 makes a bigger, bolder doily that works up faster.
Can I use size 3 crochet thread for shawls?
Yes. The maker says its size 3 drapes beautifully for shawls and accessories.
Which is better for beginners?
Size 3, because it is thicker, easier to see and works up faster. Move to size 10 once your tension is even.