These coasters are very simple to crochet and go pretty fast too. I am sharing the design here for the coasters.

I have made them using 4 ply cotton yarn and a 4mm hook. The stitches used are double crochet (dc), chain (ch), single crochet (sc) and slip stitch (sl st).

One completed coaster is approximately 4.5 inches in diameter.

You can use any yarn of your choice and the hook that suits the yarn. But do bear in mind that the size of the finished product will vary according to the yarn you choose. A thinner yarn will yield a smaller coaster and vice versa.

Material required:
Yarn - cotton 4 ply
Crochet hook - 4mm
Scissors

Instructions:

Ch 5. Sl st to first chain to form a ring.

Round 1: 10 dc in ring. Sl st to join.
Round 2: Ch 3 (counts as first dc). 1 dc in same joining stitch. 2 dc in each stitch. Sl st on top of ch 3 to join. (20 dc in all)
Round 3: Chain 3. 1 dc in same joining stitch. 1 dc in next stitch. 2 dc in next stitch. Repeat from to. Sl st on top of ch 3 to join. (30 dc in all)
Round 4: Ch 1. Sc ch 4 sc in same joining stitch. Skip one stitch. Sc Ch4 Sc in next stitch. Repeat from to. Sl st in ch 1 at the beginning of this round. (15 ch4 spaces in all)
Round 5: Sl st to ch 4 space. Ch 1. Sc Ch4 Sc in ch 4 space. Repeat from * to . Sl st in ch 1 at the beginning of this round. (15 ch4 spaces in all)

Fasten off.