Who isn't obsessed with checkerboard? This sweater already has an oversized fit, so you can stick true to size, unless you want it a little bigger. Model is wearing a size medium.
Measurements are approximate and were taken while laying flat:
X-Small: Bust: 21.5" Length: 25"
Small: Bust 22" Length 25"
Medium: Bust 23" Length 26"
Large: Bust 24: Length 26.5"