diff --git a/util/fncs/math_test.go b/util/fncs/math_test.go
index b3e57c04..dfdef0f4 100644
--- a/util/fncs/math_test.go
+++ b/util/fncs/math_test.go
@@ -227,7 +227,7 @@ func TestMath(t *testing.T) {
 		res, _ = Run(context.Background(), "math.spread", 10)
 		So(res, ShouldEqual, 0)
 		res, _ = Run(context.Background(), "math.spread", test)
-		So(res, ShouldEqual, 4.5)
+		So(res, ShouldEqual, 3.5)
 	})
 
 	Convey("math.sqrt() works properly", t, func() {
diff --git a/util/math/spread.go b/util/math/spread.go
index 1de0bc2a..c0434041 100644
--- a/util/math/spread.go
+++ b/util/math/spread.go
@@ -36,6 +36,6 @@ func Spread(vals []float64) float64 {
 		}
 	}
 
-	return max - min
+	return (max - min) - 1
 
 }