diff --git a/src/theme/size.js b/src/theme/size.js
new file mode 100644
index 00000000..13e11797
--- /dev/null
+++ b/src/theme/size.js
@@ -0,0 +1,21 @@
+// @flow
+import { xs, sm, md, lg, xl } from '~/theme/variables'
+
+export type Size = 'xs' | 'sm' | 'md' | 'lg' | 'xl'
+
+export const getSize = (size: Size) => {
+  switch (size) {
+  case 'xs':
+    return xs
+  case 'sm':
+    return sm
+  case 'md':
+    return md
+  case 'lg':
+    return lg
+  case 'xl':
+    return xl
+  default:
+    return md
+  }
+}