diff --git a/README.rst b/README.rst
index cce3023..402579a 100644
--- a/README.rst
+++ b/README.rst
@@ -12,7 +12,7 @@ Easy progress reporting for Python
 Bars
 ----
 
-There are 6 progress bars to choose from:
+There are 7 progress bars to choose from:
 
 - ``Bar``
 - ``ChargingBar``
@@ -20,6 +20,7 @@ There are 6 progress bars to choose from:
 - ``FillingCirclesBar``
 - ``IncrementalBar``
 - ``ShadyBar``
+- ``AdaptiveBar``
 
 To use them, just call ``next`` to advance and ``finish`` to finish:
 
diff --git a/progress/bar.py b/progress/bar.py
index 26008e9..12d60bb 100644
--- a/progress/bar.py
+++ b/progress/bar.py
@@ -15,7 +15,7 @@
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 from __future__ import unicode_literals
-from . import Progress
+from . import Progress, Infinite
 from .helpers import WritelnMixin
 
 
@@ -82,3 +82,41 @@ def update(self):
 
 class ShadyBar(IncrementalBar):
     phases = (' ', '░', '▒', '▓', '█')
+
+
+class AdaptiveBar(WritelnMixin, Infinite):
+    phases = (' ', '▏', '▎', '▍', '▌', '▋', '▊', '▉', '█')
+    suffix = '%(index)d%%'
+    _count = 0
+    width = 50
+    bar_prefix = ' |'
+    bar_suffix = '| '
+    empty_fill = ' '
+
+    def update(self):
+        import math
+        self.percent = float(math.pow(self._count, 2)/(math.pow(self._count, 2)+1000))
+        self.index = int(self.percent * 100)
+        self._count += 1
+        nphases = len(self.phases)
+        filled_len = self.width * self.percent
+        nfull = int(filled_len)                      # Number of full chars
+        phase = int((filled_len - nfull) * nphases)  # Phase of last char
+        nempty = self.width - nfull                  # Number of empty chars
+
+        message = self.message % self
+        bar = self.phases[-1] * nfull
+        current = self.phases[phase] if phase > 0 else ''
+        empty = self.empty_fill * max(0, nempty - len(current))
+        suffix = self.suffix % self
+        line = ''.join([message, self.bar_prefix, bar, current, empty,
+                        self.bar_suffix, suffix])
+        self.writeln(line)
+
+    def finish(self):
+        self.index = 100
+        message = self.message % self
+        suffix = self.suffix % self
+        bar = bar = self.phases[-1] * self.width
+        line = ''.join([message, self.bar_prefix, bar, self.bar_suffix, suffix])
+        self.writeln(line)
diff --git a/test_progress.py b/test_progress.py
index ae7bb19..e46e76e 100755
--- a/test_progress.py
+++ b/test_progress.py
@@ -5,7 +5,7 @@
 import random
 import time
 
-from progress.bar import (Bar, ChargingBar, FillingSquaresBar,
+from progress.bar import (Bar, ChargingBar, FillingSquaresBar, AdaptiveBar,
                           FillingCirclesBar, IncrementalBar, ShadyBar)
 from progress.spinner import Spinner, PieSpinner, MoonSpinner, LineSpinner
 from progress.counter import Counter, Countdown, Stack, Pie
@@ -16,7 +16,6 @@ def sleep():
     t += t * random.uniform(-0.1, 0.1)  # Add some variance
     time.sleep(t)
 
-
 for bar_cls in (Bar, ChargingBar, FillingSquaresBar, FillingCirclesBar):
     suffix = '%(index)d/%(max)d [%(elapsed)d / %(eta)d]'
     bar = bar_cls(bar_cls.__name__, suffix=suffix)
@@ -29,6 +28,13 @@ def sleep():
     for i in bar.iter(range(200)):
         sleep()
 
+for bar_cls in [AdaptiveBar]:
+    suffix = '%(index)d%% [%(elapsed_td)s]'
+    bar = bar_cls(bar_cls.__name__, suffix=suffix)
+    for i in bar.iter(range(200)):
+        sleep()
+    print()
+
 for spin in (Spinner, PieSpinner, MoonSpinner, LineSpinner):
     for i in spin(spin.__name__ + ' ').iter(range(100)):
         sleep()