diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96ac4856c..a980927eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### Features
 
+- [#2123](https://github.com/influxdata/telegraf/pull/2123): Fix improper calculation of CPU percentages
 - [#1564](https://github.com/influxdata/telegraf/issues/1564): Use RFC3339 timestamps in log output.
 - [#1997](https://github.com/influxdata/telegraf/issues/1997): Non-default HTTP timeouts for RabbitMQ plugin.
 - [#2074](https://github.com/influxdata/telegraf/pull/2074): "discard" output plugin added, primarily for testing purposes.
diff --git a/plugins/inputs/system/cpu.go b/plugins/inputs/system/cpu.go
index 295c0d347..3ed2606fa 100644
--- a/plugins/inputs/system/cpu.go
+++ b/plugins/inputs/system/cpu.go
@@ -91,10 +91,10 @@ func (s *CPUStats) Gather(acc telegraf.Accumulator) error {
 			continue
 		}
 		fieldsG := map[string]interface{}{
-			"usage_user":       100 * (cts.User - lastCts.User) / totalDelta,
+			"usage_user":       100 * (cts.User - lastCts.User - (cts.Guest - lastCts.Guest)) / totalDelta,
 			"usage_system":     100 * (cts.System - lastCts.System) / totalDelta,
 			"usage_idle":       100 * (cts.Idle - lastCts.Idle) / totalDelta,
-			"usage_nice":       100 * (cts.Nice - lastCts.Nice) / totalDelta,
+			"usage_nice":       100 * (cts.Nice - lastCts.Nice - (cts.GuestNice - lastCts.GuestNice)) / totalDelta,
 			"usage_iowait":     100 * (cts.Iowait - lastCts.Iowait) / totalDelta,
 			"usage_irq":        100 * (cts.Irq - lastCts.Irq) / totalDelta,
 			"usage_softirq":    100 * (cts.Softirq - lastCts.Softirq) / totalDelta,
@@ -112,7 +112,7 @@ func (s *CPUStats) Gather(acc telegraf.Accumulator) error {
 
 func totalCpuTime(t cpu.TimesStat) float64 {
 	total := t.User + t.System + t.Nice + t.Iowait + t.Irq + t.Softirq + t.Steal +
-		t.Guest + t.GuestNice + t.Idle
+		t.Idle
 	return total
 }
 
diff --git a/plugins/inputs/system/cpu_test.go b/plugins/inputs/system/cpu_test.go
index f1f659e6f..e071f22c5 100644
--- a/plugins/inputs/system/cpu_test.go
+++ b/plugins/inputs/system/cpu_test.go
@@ -17,29 +17,29 @@ func TestCPUStats(t *testing.T) {
 
 	cts := cpu.TimesStat{
 		CPU:       "cpu0",
-		User:      3.1,
+		User:      8.8,
 		System:    8.2,
 		Idle:      80.1,
 		Nice:      1.3,
-		Iowait:    0.2,
-		Irq:       0.1,
+		Iowait:    0.8389,
+		Irq:       0.6,
 		Softirq:   0.11,
 		Steal:     0.0511,
-		Guest:     8.1,
+		Guest:     3.1,
 		GuestNice: 0.324,
 	}
 
 	cts2 := cpu.TimesStat{
 		CPU:       "cpu0",
-		User:      11.4,     // increased by 8.3
+		User:      24.9,     // increased by 16.1
 		System:    10.9,     // increased by 2.7
-		Idle:      158.8699, // increased by 78.7699 (for total increase of 100)
-		Nice:      2.5,      // increased by 1.2
-		Iowait:    0.7,      // increased by 0.5
-		Irq:       1.2,      // increased by 1.1
+		Idle:      157.9798, // increased by 77.8798 (for total increase of 100)
+		Nice:      3.5,      // increased by 2.2
+		Iowait:    0.929,    // increased by 0.0901
+		Irq:       1.2,      // increased by 0.6
 		Softirq:   0.31,     // increased by 0.2
-		Steal:     0.2812,   // increased by 0.0001
-		Guest:     12.9,     // increased by 4.8
+		Steal:     0.2812,   // increased by 0.2301
+		Guest:     11.4,     // increased by 8.3
 		GuestNice: 2.524,    // increased by 2.2
 	}
 
@@ -56,15 +56,15 @@ func TestCPUStats(t *testing.T) {
 
 	// Computed values are checked with delta > 0 becasue of floating point arithmatic
 	// imprecision
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_user", 3.1, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_user", 8.8, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_system", 8.2, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_idle", 80.1, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_nice", 1.3, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_iowait", 0.2, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_irq", 0.1, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_iowait", 0.8389, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_irq", 0.6, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_softirq", 0.11, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_steal", 0.0511, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest", 8.1, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest", 3.1, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest_nice", 0.324, 0, cputags)
 
 	mps2 := MockPS{}
@@ -75,26 +75,26 @@ func TestCPUStats(t *testing.T) {
 	err = cs.Gather(&acc)
 	require.NoError(t, err)
 
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_user", 11.4, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_user", 24.9, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_system", 10.9, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_idle", 158.8699, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_nice", 2.5, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_iowait", 0.7, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_idle", 157.9798, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_nice", 3.5, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_iowait", 0.929, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_irq", 1.2, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_softirq", 0.31, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_steal", 0.2812, 0, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest", 12.9, 0, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest", 11.4, 0, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "time_guest_nice", 2.524, 0, cputags)
 
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_user", 8.3, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_user", 7.8, 0.0005, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "usage_system", 2.7, 0.0005, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_idle", 78.7699, 0.0005, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_nice", 1.2, 0.0005, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_iowait", 0.5, 0.0005, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_irq", 1.1, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_idle", 77.8798, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_nice", 0, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_iowait", 0.0901, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_irq", 0.6, 0.0005, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "usage_softirq", 0.2, 0.0005, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "usage_steal", 0.2301, 0.0005, cputags)
-	assertContainsTaggedFloat(t, &acc, "cpu", "usage_guest", 4.8, 0.0005, cputags)
+	assertContainsTaggedFloat(t, &acc, "cpu", "usage_guest", 8.3, 0.0005, cputags)
 	assertContainsTaggedFloat(t, &acc, "cpu", "usage_guest_nice", 2.2, 0.0005, cputags)
 }