Sizes: 
Small - UK 6/8
Medium - UK 10/12
Large – UK 14/16
1X Large – UK 18/20
2X Large – UK 20/22
These sizes are a guide, you can adjust to fit you
 

Hook: 6mm
I WOULD STRONGLY RECOMMEND CHECKING THE GAUGE BEFORE STARTING. I CROCHET TIGHTLY SO YOU MAY NEED TO GO UP A HOOK SIZE
 

Gauge: 
Ribbing: 10cm = 12 rows
Body (Working Dc row, then patt rows 3 & 4): 10cm = 11sts x 10 rows
 

Yarn: Aran/Worsted Cotton Can use any yarn with same gauge

Yarn I used: Knitpicks Dishie in Blush (Cotton Worsted)
https://www.knitpicks.com/yarn/dishie-yarn/c/5420207
 

Amount required: 
Small: x 6 balls approx. (100g ball)  (1140 yards)
Medium: x 6/7 balls approx. (100g ball) (1140 - 1330 yards)
Large: x 7/8 balls approx. (100g ball) (1330 -1520 yards)
1X Large: 8/9 balls approx. (100g ball) (1520 - 1710 yards)
2X Large: 10/11 balls approx. (100g ball) (1900 – 2090 yards)
 

Additional Supplies:
Buttons (approx. 1.5cm, but dependent on button hole size).
The number of button holes is customisable. For size small I created 12 button holes. This is optional! You can opt for no buttons.

Key:
St  Stitch
Ch  Chain
Sp Space
Sc  Single Crochet
Dc  Double Crochet
Dc2tog Double Crochet 2 stitches together
FPdc Front Post Double Crochet
BPdc Back Post Double Crochet
TFL Through the front loops
Sk Skip stitch
WS Wrong Side
RS Right Side
{{ }} Total stitches
( ) Additional Sizes – medium, large, 1X large & 2X Large

The photos are for size small
 
All my patterns use US terminology

This pattern is for beginner/intermediate crocheters
 
This cardigan is worked in one piece from the bottom up (so no side seam sewing, yay!)