diff --git a/lentil-soup.md b/lentil-soup.md
index c6f9c93..dc4887f 100644
--- a/lentil-soup.md
+++ b/lentil-soup.md
@@ -20,6 +20,8 @@ View with JavaScript disabled or else there is an annoying popup asking you to s
 - Juice of 1/2 lemon, more to taste
 - 3 tablespoons chopped fresh cilantro
 
+Note: I approximate 1 cup as about 250 ML, though this should be slightly less for fluid volume.
+
 ## Method
 
 - In a large pot, heat 3 tablespoons oil over high heat until hot and shimmering.