The answer to this question heavily depends on how many stitches you have on your sock and what is the toe shape you are aiming for as well as the yarn and needles you are using. Because there is not a single answer I’ve made three different interactive toe patterns having a calculator which tells you exactly when to start the toe decreases based on your row gauge and stitch count.
You might also be interested in: When to start heel on toe-up socks.
1. Wedge toe
The decreases are worked every other round on both sides of the sock until the desired stitch count is reached. Finally, the toe is closed using the Kitchener stitch or some other grafting technique.
This type of toe shaping fits especially if your foot shape is square meaning that all of your toes are almost the same length.
2. Rounded barn toe
Decreases are worked on sides of the sock so the increase lines will be visible. The first half of the increases are made every other round and the second half is worked each round which makes the toe rounder than the wedge toe.
Finally, the toe is closed using the Kitchener stitch or some other grafting technique.
3. Round toe
The decreases are distributed evenly around the sock so that the decrease lines won’t be visible.
Lastly, you take the remaining stitches, thread the yarn through and pull to close the gap.
The math behind the calculators
As mentioned before in order to calculate when to start toe decreases and make a perfectly fitting sock there are two numbers you need to know. First you need to know your row gauge which depends on the yarn and needles you are using. If you have already knitted your sock just measure how many rows per 4” or 10cm you have. The second number you need to figure out is how many rows you need to work your toe. For instance, you have 56 stitches on your sock and you are going to decrease 4 stitches every other round until you have 16 stitches remaining and then graft the toe, you need to work (56 – 16) / 4 * 2 + 1 = 21 rows to finish your toe.
Next you divide the number of rows you need to work with your row gauge and multiply that number with 4” or 10cm (or whatever is the number of inches or centimeters you counted the number of rows). So if you are going to work 21 rows and your row gauge is 44 rows / 4” you need to begin the decreases 21 / 44 * 4” = 1.9” before the desired foot length. Or if you have measured that your gauge is 22 rows / 2” the calculation will be 21 / 22 * 2” = 1.9”.
When I make socks with thin sock yarn my row gauge is usually 44 stitches per 4” (10cm). For my self I usually cast on 56 stitches and for my husband 68 stitches. On the table below you can see the difference how much before the desired foot length I need to start decreasing for the toe even when my row gauge remains the same.
|Toe shape||56 stitches||68 stitches|
|Wedge toe||1.8” (4.5cm)||2.2” (5.5cm)|
|Rounded barn toe||1.7” (4.3cm)||2.0” (5cm)|
|Rounded toe||1.9” (4.8cm)||2.7” (6.8cm)|