The phrase "calm face" is correct and can be used in written English.
For example, you could use it in a sentence such as "She wore a calm face as she entered the room."
A lion statue's magnificent, calm face is smeared with graffiti.
"Ruined — ?" she cried; but controlling herself instantly, she turned a calm face to Lily.
With her still, calm face and long floral dress, Betts appeared more serene than the garden.
The moon's calm face can make you feel, in advance, that you are understood and forgiven.
Under the F.D.N.Y. cap he wore to his postgame news conference was an extremely calm face and a reasoned demeanor.
He lay supine and motionless, his limbs outstretched, his perfectly calm face framed by the swirling mass of his hair.
I kept calm, facing forward and walking on – but that only made them more angry.
The protesters' calm faces and their belief in the possibility of radical change is probably the best – and most undeserved – compliment for a regime like Putin's.
Ingredients for Talulah serums, elixirs and body care products such as Vervain Flower Healing Complex, Blood Orange Clove Body Serum and Primrose Calming Face Serum are all 100% vegetarian and are based on naturopathic and aromatherapy principles.
In the background, Truth stands with eyes closed and a calm expression on her face.
Make sure to keep a calm look on your face, and keep your pace steady.
