diff --git a/bar.go b/bar.go
index 5828984..0c487a4 100644
--- a/bar.go
+++ b/bar.go
@@ -43,27 +43,28 @@
 
 type (
 	bState struct {
-		id               int
-		width            int
-		format           fmtRunes
-		etaAlpha         float64
-		total            int64
-		current          int64
-		dropRatio        int64
-		trimLeftSpace    bool
-		trimRightSpace   bool
-		completed        bool
-		aborted          bool
-		dynamic          bool
-		startTime        time.Time
-		timeElapsed      time.Duration
-		blockStartTime   time.Time
-		timePerItem      time.Duration
-		appendFuncs      []decor.DecoratorFunc
-		prependFuncs     []decor.DecoratorFunc
-		refill           *refill
-		bufP, bufB, bufA *bytes.Buffer
-		panic            string
+		id                   int
+		width                int
+		format               fmtRunes
+		etaAlpha             float64
+		total                int64
+		current              int64
+		totalAutoIncrTrigger int64
+		totalAutoIncrBy      int64
+		trimLeftSpace        bool
+		trimRightSpace       bool
+		completed            bool
+		aborted              bool
+		dynamic              bool
+		startTime            time.Time
+		timeElapsed          time.Duration
+		blockStartTime       time.Time
+		timePerItem          time.Duration
+		appendFuncs          []decor.DecoratorFunc
+		prependFuncs         []decor.DecoratorFunc
+		refill               *refill
+		bufP, bufB, bufA     *bytes.Buffer
+		panic                string
 	}
 	refill struct {
 		char rune
@@ -81,10 +82,10 @@
 	}
 
 	s := &bState{
-		id:        id,
-		total:     total,
-		etaAlpha:  etaAlpha,
-		dropRatio: 10,
+		id:                   id,
+		total:                total,
+		etaAlpha:             etaAlpha,
+		totalAutoIncrTrigger: 10,
 	}
 
 	for _, opt := range options {
@@ -153,8 +154,9 @@
 		}
 		s.current += int64(n)
 		if s.dynamic {
-			for s.current >= s.total {
-				s.current -= s.current * s.dropRatio / 100
+			curp := decor.CalcPercentage(s.total, s.current, 100)
+			if 100-curp <= s.totalAutoIncrTrigger {
+				s.total += s.totalAutoIncrBy
 			}
 		} else if s.current >= s.total {
 			s.current = s.total
@@ -389,30 +391,32 @@
 	// bar s.width without leftEnd and rightEnd runes
 	barWidth := width - 2
 
-	completedWidth := decor.CalcPercentage(s.total, s.current, barWidth)
+	completedWidth := decor.CalcPercentage(s.total, s.current, int64(barWidth))
 
 	if s.refill != nil {
-		till := decor.CalcPercentage(s.total, s.refill.till, barWidth)
+		till := decor.CalcPercentage(s.total, s.refill.till, int64(barWidth))
 		// append refill rune
-		for i := 0; i < till; i++ {
+		var i int64
+		for i = 0; i < till; i++ {
 			s.bufB.WriteRune(s.refill.char)
 		}
-		for i := till; i < completedWidth; i++ {
+		for i = till; i < completedWidth; i++ {
 			s.bufB.WriteRune(s.format[rFill])
 		}
 	} else {
-		for i := 0; i < completedWidth; i++ {
+		var i int64
+		for i = 0; i < completedWidth; i++ {
 			s.bufB.WriteRune(s.format[rFill])
 		}
 	}
 
-	if completedWidth < barWidth && completedWidth > 0 {
+	if completedWidth < int64(barWidth) && completedWidth > 0 {
 		_, size := utf8.DecodeLastRune(s.bufB.Bytes())
 		s.bufB.Truncate(s.bufB.Len() - size)
 		s.bufB.WriteRune(s.format[rTip])
 	}
 
-	for i := completedWidth; i < barWidth; i++ {
+	for i := completedWidth; i < int64(barWidth); i++ {
 		s.bufB.WriteRune(s.format[rEmpty])
 	}
 
diff --git a/bar_option.go b/bar_option.go
index 5c0a126..9dbd272 100644
--- a/bar_option.go
+++ b/bar_option.go
@@ -58,12 +58,20 @@
 	}
 }
 
-// BarDropRatio sets drop ratio, default is 10. Effective when total is dynamic.
-// If progress tip reaches total, but total is not final value yet, tip will be
-// dropped by specified ratio.
-func BarDropRatio(ratio int64) BarOption {
+// BarDynamicTotal enables dynamic total behaviour.
+func BarDynamicTotal() BarOption {
 	return func(s *bState) {
-		s.dropRatio = ratio
+		s.dynamic = true
+	}
+}
+
+// BarAutoIncrTotal auto increment total by amount, when trigger percentage remained till bar completion.
+// In other words: say you've set trigger = 10, then auto increment will start after bar reaches 90 %.
+func BarAutoIncrTotal(trigger, amount int64) BarOption {
+	return func(s *bState) {
+		s.dynamic = true
+		s.totalAutoIncrTrigger = trigger
+		s.totalAutoIncrBy = amount
 	}
 }
 
diff --git a/decor/decorators.go b/decor/decorators.go
index 0d0c2ba..d442e55 100644
--- a/decor/decorators.go
+++ b/decor/decorators.go
@@ -204,7 +204,7 @@
 	}
 }
 
-func CalcPercentage(total, current int64, width int) int {
+func CalcPercentage(total, current, width int64) int64 {
 	if total == 0 || current > total {
 		return 0
 	}
@@ -214,7 +214,7 @@
 	// num = 2.34 will return 2
 	// num = 2.44 will return 3
 	if math.Max(diff, 0.6) == diff {
-		return int(num)
-	}
-	return int(ceil)
-}
+		return int64(num)
+	}
+	return int64(ceil)
+}
diff --git a/examples/dynTotal/main.go b/examples/dynTotal/main.go
new file mode 100644
index 0000000..6f38a17
--- /dev/null
+++ b/examples/dynTotal/main.go
@@ -0,0 +1,51 @@
+package main
+
+import (
+	"math/rand"
+	"time"
+
+	"github.com/vbauerster/mpb"
+	"github.com/vbauerster/mpb/decor"
+)
+
+func main() {
+	p := mpb.New()
+
+	// initialize bar with dynamic total and initial total guess = 80
+	bar := p.AddBar(80,
+		// indicate that total is dynamic
+		mpb.BarDynamicTotal(),
+		// trigger total auto increment by 1, when 18 % remains till bar completion
+		mpb.BarAutoIncrTotal(18, 1),
+		mpb.PrependDecorators(
+			decor.CountersNoUnit("%d / %d", 12, 0),
+		),
+		mpb.AppendDecorators(
+			decor.Percentage(5, 0),
+		),
+	)
+
+	totalUpd1 := make(chan struct{})
+	totalUpd2 := make(chan struct{})
+	go func() {
+		<-totalUpd1
+		// intermediate not final total update
+		bar.SetTotal(200, false)
+		<-totalUpd2
+		// final total update
+		bar.SetTotal(300, true)
+	}()
+
+	for i := 0; i < 300; i++ {
+		if i == 140 {
+			close(totalUpd1)
+		}
+		if i == 250 {
+			close(totalUpd2)
+		}
+		time.Sleep(time.Duration(rand.Intn(10)+1) * time.Second / 100)
+		bar.Increment()
+	}
+
+	p.Stop()
+}