There is no set multiples for this stitch, you can make the strips as long and as wide as you need. Just make sure all of them have the same number of stitches.
You can find the links for all the squares in the crochet along here. The free pattern is below, but if you’d like the ad free printable version, it is available either as part of my Lifetime Pattern Pass, or you can purchase it on its own for £5 from Ravelry
This pattern is written in US terms, but the UK translation is below.
Double crochet (dc) = treble crochet
Single crochet (sc) = double crochet
For this square you will need a 3.5mm hook
Start by making a foundation chain of 32.
Row 1. Make a dc in the 4th chain from your hook (the turning chain counts as a stitch) dc in each stitch across
Alternate turning chain in the first stitch. Dc in each stitch across.
Tie off and weave in ends. Make 12 of these strips.
We’re going to join all the strips together by using the sc border.
Start by laying one strip across, then arrange 6 of the strips in lengths, alternating them on top and below the strip you laid across.
Now we will crochet them together with sc. Each strip going down in the picture above needs 5 sc in the side (3sc in the side of 1 dc row, 2 in the other). For the strip going across in the picture there will be a sc in each stitch – 30 sc in total
You will be going through both strips with each sc you make. Use a standing sc to make your first stitch.
Join all the strips together. When you get to the end, add an extra sc in the corner for the turn, then turn the strips and lay another strip down arranging the rest of the strips in the same alternating pattern as the first side. Join them all in the same way adding an extra sc for the turn at the end of the row.
You should now have all your strips joined on at least 1 side.
On the 3rd side we need to start weaving the strips together before joining the edges. Make sure each strip is weaved under and over before joining then at the edges. Add an extra stitch in the corner for the turn.
Repeat the same for the 4th side. Some of your strips may need a tug to stretch, but they will be long enough. Add an extra sc for the turn before joining into the first sc on the 1st side
You should have 30 sc down each side, plus an extra stitch in each corner for the turn. This will make your stitch count as 32 stitches across each side and 124 stitches total (remember the extra stitch corner stitch is counted in the stitch count for both sides)
You have now finished your square and join and you can tie off and weave in the ends
You can now add the interlocking border, joining this weeks square to last weeks as you join. You can see how to do this here
If you have any questions about the pattern or the CAL, then come on over to the Facebook group – 50 Stitches where you can show us your completed squares too.