diff --git a/decor/size_type.go b/decor/size_type.go
index c5f3a53..e4b9740 100644
--- a/decor/size_type.go
+++ b/decor/size_type.go
@@ -5,7 +5,6 @@
 	"io"
 	"math"
 	"strconv"
-	"strings"
 )
 
 //go:generate stringer -type=SizeB1024 -trimprefix=_i
@@ -52,29 +51,12 @@
 		unit = _iTiB
 	}
 
-	var b strings.Builder
-	b.WriteString(strconv.FormatFloat(float64(self)/float64(unit), 'f', prec, 64))
+	io.WriteString(st, strconv.FormatFloat(float64(self)/float64(unit), 'f', prec, 64))
 
 	if st.Flag(' ') {
-		b.WriteString(" ")
+		io.WriteString(st, " ")
 	}
-	b.WriteString(unit.String())
-
-	if w, ok := st.Width(); ok {
-		if l := b.Len(); l < w {
-			pad := strings.Repeat(" ", w-l)
-			if st.Flag('-') {
-				b.WriteString(pad)
-			} else {
-				tmp := b.String()
-				b.Reset()
-				b.WriteString(pad)
-				b.WriteString(tmp)
-			}
-		}
-	}
-
-	io.WriteString(st, b.String())
+	io.WriteString(st, unit.String())
 }
 
 const (
@@ -118,27 +100,10 @@
 		unit = _TB
 	}
 
-	var b strings.Builder
-	b.WriteString(strconv.FormatFloat(float64(self)/float64(unit), 'f', prec, 64))
+	io.WriteString(st, strconv.FormatFloat(float64(self)/float64(unit), 'f', prec, 64))
 
 	if st.Flag(' ') {
-		b.WriteString(" ")
+		io.WriteString(st, " ")
 	}
-	b.WriteString(unit.String())
-
-	if w, ok := st.Width(); ok {
-		if l := b.Len(); l < w {
-			pad := strings.Repeat(" ", w-l)
-			if st.Flag('-') {
-				b.WriteString(pad)
-			} else {
-				tmp := b.String()
-				b.Reset()
-				b.WriteString(pad)
-				b.WriteString(tmp)
-			}
-		}
-	}
-
-	io.WriteString(st, b.String())
+	io.WriteString(st, unit.String())
 }
diff --git a/decor/size_type_test.go b/decor/size_type_test.go
index 2bae4a6..8601e25 100644
--- a/decor/size_type_test.go
+++ b/decor/size_type_test.go
@@ -22,26 +22,6 @@
 		"verb % .1f": {12345678, "% .1f", "11.8 MiB"},
 		"verb % .2f": {12345678, "% .2f", "11.77 MiB"},
 		"verb % .3f": {12345678, "% .3f", "11.774 MiB"},
-
-		"verb %8.f":  {12345678, "%8.f", "   12MiB"},
-		"verb %8.0f": {12345678, "%8.0f", "   12MiB"},
-		"verb %8.1f": {12345678, "%8.1f", " 11.8MiB"},
-		"verb %8.2f": {12345678, "%8.2f", "11.77MiB"},
-		"verb %8.3f": {12345678, "%8.3f", "11.774MiB"},
-
-		"verb % 8.f":  {12345678, "% 8.f", "  12 MiB"},
-		"verb % 8.0f": {12345678, "% 8.0f", "  12 MiB"},
-		"verb % 8.1f": {12345678, "% 8.1f", "11.8 MiB"},
-
-		"verb %-8.f":  {12345678, "%-8.f", "12MiB   "},
-		"verb %-8.0f": {12345678, "%-8.0f", "12MiB   "},
-		"verb %-8.1f": {12345678, "%-8.1f", "11.8MiB "},
-		"verb %-8.2f": {12345678, "%8.2f", "11.77MiB"},
-		"verb %-8.3f": {12345678, "%8.3f", "11.774MiB"},
-
-		"verb % -8.f":  {12345678, "% -8.f", "12 MiB  "},
-		"verb % -8.0f": {12345678, "% -8.0f", "12 MiB  "},
-		"verb % -8.1f": {12345678, "% -8.1f", "11.8 MiB"},
 
 		"1000 %f":           {1000, "%f", "1000.000000b"},
 		"1000 %d":           {1000, "%d", "1000b"},
@@ -91,26 +71,6 @@
 		"verb % .2f": {12345678, "% .2f", "12.35 MB"},
 		"verb % .3f": {12345678, "% .3f", "12.346 MB"},
 
-		"verb %8.f":  {12345678, "%8.f", "    12MB"},
-		"verb %8.0f": {12345678, "%8.0f", "    12MB"},
-		"verb %8.1f": {12345678, "%8.1f", "  12.3MB"},
-		"verb %8.2f": {12345678, "%8.2f", " 12.35MB"},
-		"verb %8.3f": {12345678, "%8.3f", "12.346MB"},
-
-		"verb % 8.f":  {12345678, "% 8.f", "   12 MB"},
-		"verb % 8.0f": {12345678, "% 8.0f", "   12 MB"},
-		"verb % 8.1f": {12345678, "% 8.1f", " 12.3 MB"},
-
-		"verb %-8.f":  {12345678, "%-8.f", "12MB    "},
-		"verb %-8.0f": {12345678, "%-8.0f", "12MB    "},
-		"verb %-8.1f": {12345678, "%-8.1f", "12.3MB  "},
-		"verb %-8.2f": {12345678, "%8.2f", " 12.35MB"},
-		"verb %-8.3f": {12345678, "%8.3f", "12.346MB"},
-
-		"verb % -8.f":  {12345678, "% -8.f", "12 MB   "},
-		"verb % -8.0f": {12345678, "% -8.0f", "12 MB   "},
-		"verb % -8.1f": {12345678, "% -8.1f", "12.3 MB "},
-
 		"1000 %f":          {1000, "%f", "1.000000KB"},
 		"1000 %d":          {1000, "%d", "1KB"},
 		"1000 %s":          {1000, "%s", "1KB"},
diff --git a/decor/speed.go b/decor/speed.go
index e90b0ff..2512e01 100644
--- a/decor/speed.go
+++ b/decor/speed.go
@@ -2,11 +2,33 @@
 
 import (
 	"fmt"
+	"io"
 	"math"
 	"time"
 
 	"github.com/VividCortex/ewma"
 )
+
+const (
+	perSecond = "/s"
+)
+
+type speedType struct {
+	sizeT     fmt.Formatter
+	perSecond string
+}
+
+func (self *speedType) Format(st fmt.State, verb rune) {
+	self.sizeT.Format(st, verb)
+	io.WriteString(st, self.perSecond)
+}
+
+func sizePerSecond(sizeT fmt.Formatter) fmt.Formatter {
+	return &speedType{
+		sizeT:     sizeT,
+		perSecond: perSecond,
+	}
+}
 
 // EwmaSpeed exponential-weighted-moving-average based speed decorator.
 // Note that it's necessary to supply bar.Incr* methods with incremental
@@ -42,9 +64,6 @@
 	wc.Init()
 	if fmt == "" {
 		fmt = "%.0f"
-	}
-	if unit > 0 {
-		fmt += "/s"
 	}
 	d := &movingAverageSpeed{
 		WC:      wc,
@@ -135,9 +154,6 @@
 	if fmt == "" {
 		fmt = "%.0f"
 	}
-	if unit > 0 {
-		fmt += "/s"
-	}
 	d := &averageSpeed{
 		WC:        wc,
 		unit:      unit,
@@ -169,9 +185,9 @@
 
 	switch d.unit {
 	case UnitKiB:
-		d.msg = fmt.Sprintf(d.fmt, SizeB1024(math.Round(speed)))
+		d.msg = fmt.Sprintf(d.fmt, sizePerSecond(SizeB1024(math.Round(speed))))
 	case UnitKB:
-		d.msg = fmt.Sprintf(d.fmt, SizeB1000(math.Round(speed)))
+		d.msg = fmt.Sprintf(d.fmt, sizePerSecond(SizeB1000(math.Round(speed))))
 	default:
 		d.msg = fmt.Sprintf(d.fmt, speed)
 	}