diff --git a/layout/layout.go b/layout/layout.go
index 2a6a6732..8d3a3d12 100644
--- a/layout/layout.go
+++ b/layout/layout.go
@@ -58,6 +58,14 @@ const (
 	Vertical
 )
 
+// Exact returns the Constraints with the minimum and maximum size
+// set to size.
+func Exact(size image.Point) Constraints {
+	return Constraints{
+		Min: size, Max: size,
+	}
+}
+
 // Constrain a size so each dimension is in the range [min;max].
 func (c Constraints) Constrain(size image.Point) image.Point {
 	if min := c.Min.X; size.X < min {