diff --git a/include/vector/vec.h b/include/vector/vec.h
index b0c8299..09f9633 100644
--- a/include/vector/vec.h
+++ b/include/vector/vec.h
@@ -128,6 +128,7 @@ mat4x4f_t get_scaling_matrix(vec3f_t scale);
 mat3x3f_t get_rotation_mat3x3f(vec3f_t rotation);
 vec3f_t mul_mat3x4f_by_vec4f(mat3x4f_t mat, vec4f_t vec);
 mat3x4f_t mul_mat3x4f_by_mat4x4f(mat3x4f_t mat1, mat4x4f_t mat2);
+vec4f_t mul_mat4x4f_by_vec4f(mat4x4f_t mat, vec4f_t vec);
 mat4x4f_t mul_mat4x4f(mat4x4f_t mat1, mat4x4f_t mat2);
 
 #endif // !VEC_H
diff --git a/src/vector/vec.c b/src/vector/vec.c
index 133d7e4..66ca772 100644
--- a/src/vector/vec.c
+++ b/src/vector/vec.c
@@ -342,6 +342,19 @@ mat3x4f_t mul_mat3x4f_by_mat4x4f(mat3x4f_t mat1, mat4x4f_t mat2) {
   };
 }
 
+vec4f_t mul_mat4x4f_by_vec4f(mat4x4f_t mat, vec4f_t vec) {
+  f32 x = mat.row0.x * vec.x + mat.row0.y * vec.y + mat.row0.z * vec.z +
+          mat.row0.w * vec.w;
+  f32 y = mat.row1.x * vec.x + mat.row1.y * vec.y + mat.row1.z * vec.z +
+          mat.row1.w * vec.w;
+  f32 z = mat.row2.x * vec.x + mat.row2.y * vec.y + mat.row2.z * vec.z +
+          mat.row2.w * vec.w;
+  f32 w = mat.row3.x * vec.x + mat.row3.y * vec.y + mat.row3.z * vec.z +
+          mat.row3.w * vec.w;
+
+  return (vec4f_t){x, y, z, w};
+}
+
 mat4x4f_t mul_mat4x4f(mat4x4f_t mat1, mat4x4f_t mat2) {
   f32 row0_col0 = mat1.row0.x * mat2.row0.x + mat1.row0.y * mat2.row1.x +
                   mat1.row0.z * mat2.row2.x + mat1.row0.w * mat2.row3.x;