diff --git a/decor/decorators.go b/decor/decorators.go
index d442e55..e66108b 100644
--- a/decor/decorators.go
+++ b/decor/decorators.go
@@ -204,10 +204,14 @@
 	}
 }
 
-func CalcPercentage(total, current, width int64) int64 {
-	if total == 0 || current > total {
+func CalcPercentage(total, current, width int64) (perc int64) {
+	if total <= 0 {
 		return 0
 	}
+	if current > total {
+		current = total
+	}
+
 	num := float64(width) * float64(current) / float64(total)
 	ceil := math.Ceil(num)
 	diff := ceil - num
diff --git a/decor/percentage_test.go b/decor/percentage_test.go
new file mode 100644
index 0000000..e0672bb
--- /dev/null
+++ b/decor/percentage_test.go
@@ -0,0 +1,68 @@
+package decor
+
+import "testing"
+
+func TestCalcPersentage(t *testing.T) {
+	// key is barWidth
+	testSuite := map[int64]map[string]struct {
+		total, current, expected int64
+	}{
+		100: {
+			"t,c,e{-1,-1,0}":     {-1, -1, 0},
+			"t,c,e{0,-1,0}":      {0, -1, 0},
+			"t,c,e{0,0,0}":       {0, 0, 0},
+			"t,c,e{0,1,0}":       {0, 1, 0},
+			"t,c,e{100,0,0}":     {100, 0, 0},
+			"t,c,e{100,10,10}":   {100, 10, 10},
+			"t,c,e{100,15,15}":   {100, 15, 15},
+			"t,c,e{100,50,50}":   {100, 50, 50},
+			"t,c,e{100,99,99}":   {100, 99, 99},
+			"t,c,e{100,100,100}": {100, 100, 100},
+			"t,c,e{100,101,100}": {100, 101, 100},
+			"t,c,e{120,0,0}":     {120, 0, 0},
+			"t,c,e{120,10,8}":    {120, 10, 8},
+			"t,c,e{120,15,13}":   {120, 15, 13},
+			"t,c,e{120,50,42}":   {120, 50, 42},
+			"t,c,e{120,60,50}":   {120, 60, 50},
+			"t,c,e{120,99,83}":   {120, 99, 83},
+			"t,c,e{120,101,84}":  {120, 101, 84},
+			"t,c,e{120,118,98}":  {120, 118, 98},
+			"t,c,e{120,119,99}":  {120, 119, 99},
+			"t,c,e{120,120,100}": {120, 120, 100},
+			"t,c,e{120,121,100}": {120, 121, 100},
+		},
+		80: {
+			"t,c,e{-1,-1,0}":    {-1, -1, 0},
+			"t,c,e{0,-1,0}":     {0, -1, 0},
+			"t,c,e{0,0,0}":      {0, 0, 0},
+			"t,c,e{0,1,0}":      {0, 1, 0},
+			"t,c,e{100,0,0}":    {100, 0, 0},
+			"t,c,e{100,10,8}":   {100, 10, 8},
+			"t,c,e{100,15,12}":  {100, 15, 12},
+			"t,c,e{100,50,40}":  {100, 50, 40},
+			"t,c,e{100,99,79}":  {100, 99, 79},
+			"t,c,e{100,100,80}": {100, 100, 80},
+			"t,c,e{100,101,80}": {100, 101, 80},
+			"t,c,e{120,0,0}":    {120, 0, 0},
+			"t,c,e{120,10,7}":   {120, 10, 7},
+			"t,c,e{120,15,10}":  {120, 15, 10},
+			"t,c,e{120,50,33}":  {120, 50, 33},
+			"t,c,e{120,60,40}":  {120, 60, 40},
+			"t,c,e{120,99,66}":  {120, 99, 66},
+			"t,c,e{120,101,67}": {120, 101, 67},
+			"t,c,e{120,118,79}": {120, 118, 79},
+			"t,c,e{120,119,79}": {120, 119, 79},
+			"t,c,e{120,120,80}": {120, 120, 80},
+			"t,c,e{120,121,80}": {120, 121, 80},
+		},
+	}
+
+	for width, cases := range testSuite {
+		for name, tc := range cases {
+			got := CalcPercentage(tc.total, tc.current, width)
+			if got != tc.expected {
+				t.Errorf("width %d; %s: Expected: %d, got: %d\n", width, name, tc.expected, got)
+			}
+		}
+	}
+}
diff --git a/draw_test.go b/draw_test.go
index 7bd6967..c056fcf 100644
--- a/draw_test.go
+++ b/draw_test.go
@@ -6,113 +6,194 @@
 )
 
 func TestFillBar(t *testing.T) {
-	tests := []struct {
-		termWidth int
-		barWidth  int
-		total     int64
-		current   int64
-		barRefill *refill
-		want      string
+	// key is termWidth
+	testSuite := map[int]map[string]struct {
+		total, current int64
+		barWidth       int
+		barRefill      *refill
+		want           string
 	}{
-		{
-			termWidth: 2,
-			barWidth:  100,
-			want:      "[]",
-		},
-		{
-			termWidth: 3,
-			barWidth:  100,
-			total:     100,
-			current:   20,
-			want:      "[-]",
-		},
-		{
-			termWidth: 5,
-			barWidth:  100,
-			total:     100,
-			current:   20,
-			want:      "[>--]",
-		},
-		{
-			termWidth: 6,
-			barWidth:  100,
-			total:     100,
-			current:   20,
-			want:      "[>---]",
-		},
-		{
-			termWidth: 20,
-			barWidth:  100,
-			total:     100,
-			current:   20,
-			want:      "[===>--------------]",
-		},
-		{
-			termWidth: 50,
-			barWidth:  100,
-			total:     100,
-			current:   20,
-			want:      "[=========>--------------------------------------]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   0,
-			want:      "[--------------------------------------------------------------------------------------------------]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   1,
-			want:      "[>-------------------------------------------------------------------------------------------------]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   40,
-			want:      "[======================================>-----------------------------------------------------------]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   40,
-			barRefill: &refill{'+', 32},
-			want:      "[+++++++++++++++++++++++++++++++=======>-----------------------------------------------------------]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   99,
-			want:      "[================================================================================================>-]",
-		},
-		{
-			termWidth: 100,
-			barWidth:  100,
-			total:     100,
-			current:   100,
-			want:      "[==================================================================================================]",
+		100: {
+			"t,c,bw{100,100,0}": {
+				total:    100,
+				current:  0,
+				barWidth: 100,
+				want:     "[--------------------------------------------------------------------------------------------------]",
+			},
+			"t,c,bw{100,1,100}": {
+				total:    100,
+				current:  1,
+				barWidth: 100,
+				want:     "[>-------------------------------------------------------------------------------------------------]",
+			},
+			"t,c,bw{100,40,100}": {
+				total:    100,
+				current:  40,
+				barWidth: 100,
+				want:     "[======================================>-----------------------------------------------------------]",
+			},
+			"t,c,bw{100,40,100}refill{'+', 32}": {
+				total:     100,
+				current:   40,
+				barWidth:  100,
+				barRefill: &refill{'+', 32},
+				want:      "[+++++++++++++++++++++++++++++++=======>-----------------------------------------------------------]",
+			},
+			"t,c,bw{100,99,100}": {
+				total:    100,
+				current:  99,
+				barWidth: 100,
+				want:     "[================================================================================================>-]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[==================================================================================================]",
+			},
+		},
+		2: {
+			"t,c,bw{0,0,100}": {
+				barWidth: 100,
+				want:     "[]",
+			},
+			"t,c,bw{60,20,80}": {
+				total:    60,
+				current:  20,
+				barWidth: 80,
+				want:     "[]",
+			},
+		},
+		3: {
+			"t,c,bw{100,20,100}": {
+				total:    100,
+				current:  20,
+				barWidth: 100,
+				want:     "[-]",
+			},
+			"t,c,bw{100,98,100}": {
+				total:    100,
+				current:  98,
+				barWidth: 100,
+				want:     "[=]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[=]",
+			},
+		},
+		5: {
+			"t,c,bw{100,20,100}": {
+				total:    100,
+				current:  20,
+				barWidth: 100,
+				want:     "[>--]",
+			},
+			"t,c,bw{100,98,100}": {
+				total:    100,
+				current:  98,
+				barWidth: 100,
+				want:     "[===]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[===]",
+			},
+		},
+		6: {
+			"t,c,bw{100,20,100}": {
+				total:    100,
+				current:  20,
+				barWidth: 100,
+				want:     "[>---]",
+			},
+			"t,c,bw{100,98,100}": {
+				total:    100,
+				current:  98,
+				barWidth: 100,
+				want:     "[====]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[====]",
+			},
+		},
+		20: {
+			"t,c,bw{100,20,100}": {
+				total:    100,
+				current:  20,
+				barWidth: 100,
+				want:     "[===>--------------]",
+			},
+			"t,c,bw{100,60,100}": {
+				total:    100,
+				current:  60,
+				barWidth: 100,
+				want:     "[==========>-------]",
+			},
+			"t,c,bw{100,98,100}": {
+				total:    100,
+				current:  98,
+				barWidth: 100,
+				want:     "[==================]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[==================]",
+			},
+		},
+		50: {
+			"t,c,bw{100,20,100}": {
+				total:    100,
+				current:  20,
+				barWidth: 100,
+				want:     "[=========>--------------------------------------]",
+			},
+			"t,c,bw{100,60,100}": {
+				total:    100,
+				current:  60,
+				barWidth: 100,
+				want:     "[============================>-------------------]",
+			},
+			"t,c,bw{100,98,100}": {
+				total:    100,
+				current:  98,
+				barWidth: 100,
+				want:     "[==============================================>-]",
+			},
+			"t,c,bw{100,100,100}": {
+				total:    100,
+				current:  100,
+				barWidth: 100,
+				want:     "[================================================]",
+			},
 		},
 	}
 
 	prependWs := newWidthSync(nil, 1, 0)
 	appendWs := newWidthSync(nil, 1, 0)
-	for _, test := range tests {
-		s := newTestState()
-		s.width = test.barWidth
-		s.total = test.total
-		s.current = test.current
-		if test.barRefill != nil {
-			s.refill = test.barRefill
-		}
-		s.draw(test.termWidth, prependWs, appendWs)
-		got := s.bufB.String()
-		if got != test.want {
-			t.Errorf("Want: %q, Got: %q\n", test.want, got)
+	for termWidth, cases := range testSuite {
+		for name, tc := range cases {
+			s := newTestState()
+			s.width = tc.barWidth
+			s.total = tc.total
+			s.current = tc.current
+			if tc.barRefill != nil {
+				s.refill = tc.barRefill
+			}
+			s.draw(termWidth, prependWs, appendWs)
+			got := s.bufB.String()
+			if got != tc.want {
+				t.Errorf("termWidth %d; %s: want: %s %d, got: %s %d\n", termWidth, name, tc.want, len(tc.want), got, len(got))
+			}
 		}
 	}
 }