diff --git a/robotgo.go b/robotgo.go
index eebf90f..bcc4f6d 100644
--- a/robotgo.go
+++ b/robotgo.go
@@ -305,8 +305,8 @@ func Mul(x int) int {
 // GetScaleSize get the screen scale size
 func GetScaleSize() (int, int) {
 	x, y := GetScreenSize()
-	s := Scale()
-	return x * s / 100, y * s / 100
+	f := ScaleF()
+	return int(float64(x) * f), int(float64(y) * f)
 }
 
 // SetXDisplayName set XDisplay name (Linux)
diff --git a/robotgo_mac.go b/robotgo_mac.go
new file mode 100644
index 0000000..d01706f
--- /dev/null
+++ b/robotgo_mac.go
@@ -0,0 +1,19 @@
+// Copyright 2016 The go-vgo Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// https://github.com/go-vgo/robotgo/blob/master/LICENSE
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//go:build !windows
+// +build !windows
+
+package robotgo
+
+// ScaleF get the system scale val
+func ScaleF() float64 {
+	return SysScale()
+}
diff --git a/robotgo_win.go b/robotgo_win.go
index 46a3808..ba7bb58 100644
--- a/robotgo_win.go
+++ b/robotgo_win.go
@@ -21,16 +21,14 @@ import (
 )
 
 // FindWindow find window hwnd by name
-func FindWindow(str string) win.HWND {
-	hwnd := win.FindWindow(nil, syscall.StringToUTF16Ptr(str))
-
+func FindWindow(name string) win.HWND {
+	hwnd := win.FindWindow(nil, syscall.StringToUTF16Ptr(name))
 	return hwnd
 }
 
 // GetHWND get foreground window hwnd
 func GetHWND() win.HWND {
 	hwnd := win.GetForegroundWindow()
-
 	return hwnd
 }
 
@@ -50,6 +48,26 @@ func SetActiveWindow(hwnd win.HWND) win.HWND {
 }
 
 // SetFocus set window focus with hwnd
-func SetFocus(hWnd win.HWND) win.HWND {
+func SetFocus(hwnd win.HWND) win.HWND {
 	return win.SetFocus(hWnd)
 }
+
+// ScaleF get the system scale val
+func ScaleF() float64 {
+	return float64(GetMainDPI()) / 96.0
+}
+
+// GetMainDPI get the display dpi
+func GetMainDPI() int {
+	return int(GetDPI(GetHWND()))
+}
+
+// GetDPI get the window dpi
+func GetDPI(hwnd win.HWND) uint32 {
+	return win.GetDpiForWindow(hwnd)
+}
+
+// GetSysDPI get the system metrics dpi
+func GetSysDPI(idx int32, dpi uint32) int32 {
+	return win.GetSystemMetricsForDpi(idex, dpi)
+}