diff --git a/agent/router/manager_internal_test.go b/agent/router/manager_internal_test.go
index 05807e2070..e172345fac 100644
--- a/agent/router/manager_internal_test.go
+++ b/agent/router/manager_internal_test.go
@@ -8,9 +8,11 @@ import (
 	"testing"
 	"time"
 
-	"github.com/hashicorp/consul/agent/metadata"
 	"github.com/hashicorp/go-hclog"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/hashicorp/consul/agent/metadata"
 )
 
 var (
@@ -262,55 +264,77 @@ func test_reconcileServerList(maxServers int) (bool, error) {
 	return true, nil
 }
 
-// func (l *serverList) refreshServerRebalanceTimer() {
-func TestManagerInternal_refreshServerRebalanceTimer(t *testing.T) {
-	type clusterSizes struct {
-		numNodes     int
-		numServers   int
-		minRebalance time.Duration
-	}
-	clusters := []clusterSizes{
-		{0, 3, 2 * time.Minute},
-		{1, 0, 2 * time.Minute}, // partitioned cluster
-		{1, 3, 2 * time.Minute},
-		{2, 3, 2 * time.Minute},
-		{100, 0, 2 * time.Minute}, // partitioned
-		{100, 1, 2 * time.Minute}, // partitioned
-		{100, 3, 2 * time.Minute},
-		{1024, 1, 2 * time.Minute}, // partitioned
-		{1024, 3, 2 * time.Minute}, // partitioned
-		{1024, 5, 2 * time.Minute},
-		{16384, 1, 4 * time.Minute}, // partitioned
-		{16384, 2, 2 * time.Minute}, // partitioned
-		{16384, 3, 2 * time.Minute}, // partitioned
-		{16384, 5, 2 * time.Minute},
-		{65535, 0, 2 * time.Minute}, // partitioned
-		{65535, 1, 8 * time.Minute}, // partitioned
-		{65535, 2, 3 * time.Minute}, // partitioned
-		{65535, 3, 5 * time.Minute}, // partitioned
-		{65535, 5, 3 * time.Minute}, // partitioned
-		{65535, 7, 2 * time.Minute},
-		{1000000, 1, 4 * time.Hour},     // partitioned
-		{1000000, 2, 2 * time.Hour},     // partitioned
-		{1000000, 3, 80 * time.Minute},  // partitioned
-		{1000000, 5, 50 * time.Minute},  // partitioned
-		{1000000, 11, 20 * time.Minute}, // partitioned
-		{1000000, 19, 10 * time.Minute},
+func TestManager_refreshServerRebalanceTimer(t *testing.T) {
+	type testCase struct {
+		servers  int
+		nodes    int
+		expected time.Duration
 	}
 
-	logger := GetBufferedLogger()
-	shutdownCh := make(chan struct{})
+	testCases := []testCase{
+		{servers: 0, nodes: 1},
+		{servers: 0, nodes: 100},
+		{servers: 0, nodes: 65535},
+		{servers: 0, nodes: 1000000},
 
-	for _, s := range clusters {
-		m := New(logger, shutdownCh, &fauxSerf{numNodes: s.numNodes}, &fauxConnPool{}, "", noopRebalancer)
-		for i := 0; i < s.numServers; i++ {
-			nodeName := fmt.Sprintf("s%02d", i)
-			m.AddServer(&metadata.Server{Name: nodeName})
+		{servers: 1, nodes: 100},
+		{servers: 1, nodes: 1024},
+		{servers: 1, nodes: 8192},
+		{servers: 1, nodes: 11520},
+		{servers: 1, nodes: 11521, expected: 3*time.Minute + 15625*time.Microsecond},
+		{servers: 1, nodes: 16384, expected: 4*time.Minute + 16*time.Second},
+		{servers: 1, nodes: 65535, expected: 17*time.Minute + 3984375000},
+		{servers: 1, nodes: 1000000, expected: 4*time.Hour + 20*time.Minute + 25*time.Second},
+
+		{servers: 2, nodes: 100},
+		{servers: 2, nodes: 16384},
+		{servers: 2, nodes: 23040},
+		{servers: 2, nodes: 23041, expected: 3*time.Minute + 7812500},
+		{servers: 2, nodes: 65535, expected: 8*time.Minute + 31992187500},
+		{servers: 2, nodes: 1000000, expected: 2*time.Hour + 10*time.Minute + 12500*time.Millisecond},
+
+		{servers: 3, nodes: 0},
+		{servers: 3, nodes: 100},
+		{servers: 3, nodes: 1024},
+		{servers: 3, nodes: 16384},
+		{servers: 3, nodes: 34560},
+		{servers: 3, nodes: 34561, expected: 3*time.Minute + 5208333},
+		{servers: 3, nodes: 65535, expected: 5*time.Minute + 41328125000},
+		{servers: 3, nodes: 1000000, expected: 86*time.Minute + 48333333333},
+
+		{servers: 5, nodes: 0},
+		{servers: 5, nodes: 1024},
+		{servers: 5, nodes: 16384},
+		{servers: 5, nodes: 32768},
+		{servers: 5, nodes: 57600},
+		{servers: 5, nodes: 65535, expected: 3*time.Minute + 24796875000},
+		{servers: 5, nodes: 1000000, expected: 52*time.Minute + 5*time.Second},
+
+		{servers: 7, nodes: 65535},
+		{servers: 7, nodes: 80500},
+		{servers: 7, nodes: 131070, expected: 4*time.Minute + 52566964285},
+
+		{servers: 11, nodes: 1000000, expected: 23*time.Minute + 40454545454},
+		{servers: 19, nodes: 1000000, expected: 13*time.Minute + 42368421052},
+	}
+
+	for _, tc := range testCases {
+		m := &Manager{clusterInfo: &fauxSerf{numNodes: tc.nodes}, rebalanceTimer: time.NewTimer(0)}
+		m.saveServerList(serverList{servers: make([]*metadata.Server, tc.servers)})
+		delay := m.refreshServerRebalanceTimer()
+
+		if tc.expected != 0 {
+			assert.Equal(t, tc.expected, delay, "nodes=%d, servers=%d", tc.nodes, tc.servers)
+			continue
 		}
 
-		d := m.refreshServerRebalanceTimer()
-		if d < s.minRebalance {
-			t.Errorf("duration too short for cluster of size %d and %d servers (%s < %s)", s.numNodes, s.numServers, d, s.minRebalance)
+		min := 2 * time.Minute
+		max := 3 * time.Minute
+		if delay < min {
+			t.Errorf("nodes=%d, servers=%d, expected >%v, actual %v", tc.nodes, tc.servers, min, delay)
+		}
+		if delay > max {
+			t.Errorf("nodes=%d, servers=%d, expected <%v, actual %v", tc.nodes, tc.servers, max, delay)
 		}
 	}
 }