diff --git a/src/test/unittests/synergy/DpiHelperTests.cpp b/src/test/unittests/synergy/DpiHelperTests.cpp
new file mode 100644
index 00000000..77527998
--- /dev/null
+++ b/src/test/unittests/synergy/DpiHelperTests.cpp
@@ -0,0 +1,70 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "synergy/DpiHelper.h"
+
+#include "test/global/gtest.h"
+
+void resetStaticVariables()
+{
+	DpiHelper::s_resolutionWidth = 0;
+	DpiHelper::s_resolutionHeight = 0;
+	DpiHelper::s_primaryWidthCenter = 0;
+	DpiHelper::s_primaryHeightCenter = 0;
+	DpiHelper::s_dpi = DpiHelper::kDefaultDpi;
+	DpiHelper::s_dpiScaled = false;
+}
+
+TEST(DpiHelperTests, calculateDpi_samePhysicalAndVirtualResolutions_defaultDpi)
+{
+	resetStaticVariables();
+
+	DpiHelper::s_resolutionWidth = 1920;
+	DpiHelper::s_resolutionHeight = 1080;
+	DpiHelper::s_primaryWidthCenter = 960;
+	DpiHelper::s_primaryHeightCenter = 540;
+
+	DpiHelper::calculateDpi(1920, 1080);
+
+	EXPECT_EQ(false, DpiHelper::s_dpiScaled);
+	EXPECT_EQ(DpiHelper::kDefaultDpi, DpiHelper::s_dpi);
+}
+
+TEST(DpiHelperTests, calculateDpi_differentPhysicalAndVirtualResolutions_scaledDpi)
+{
+	resetStaticVariables();
+
+	DpiHelper::s_resolutionWidth = 1920;
+	DpiHelper::s_resolutionHeight = 1080;
+	DpiHelper::s_primaryWidthCenter = 960;
+	DpiHelper::s_primaryHeightCenter = 540;
+
+	DpiHelper::calculateDpi(960, 540);
+
+	EXPECT_EQ(true, DpiHelper::s_dpiScaled);
+	EXPECT_EQ(200, DpiHelper::s_dpi);
+}
+
+TEST(DpiHelperTests, calculateDpi_defaultStaticValues_defaultDpi)
+{
+	resetStaticVariables();
+
+	DpiHelper::calculateDpi(1920, 1080);
+
+	EXPECT_EQ(false, DpiHelper::s_dpiScaled);
+	EXPECT_EQ(DpiHelper::kDefaultDpi, DpiHelper::s_dpi);
+}