diff --git a/ecc.h b/ecc.h
index b78e86d..07d8bc8 100644
--- a/ecc.h
+++ b/ecc.h
@@ -124,6 +124,14 @@ ecc_point_mul (struct ecc_point *r, const struct ecc_scalar *n,
 void
 ecc_point_mul_g (struct ecc_point *r, const struct ecc_scalar *n);
 
+/* Returns the size in bytes needed to store a coordinate of the curve.
+ */
+inline static unsigned
+ecc_coordinate_size (const struct ecc_curve *ecc)
+{
+	return (ecc->bit_size+7)/8;
+}
+
 
 /* Low-level interface */