diff --git a/thin-provisioning/thin_metadata_size b/thin-provisioning/thin_metadata_size
index 37ca564..3e90e86 100755
--- a/thin-provisioning/thin_metadata_size
+++ b/thin-provisioning/thin_metadata_size
@@ -18,51 +18,48 @@ require 'pathname'
 $prg = Pathname.new($0).basename
 
 def init_units
-  units = Hash.new
-  units[:chars] = "sKkMmGgTtPpEeZzYy"
-  units[:strings] = [ 'sectors',
+  units = {}
+  units[:bytes_per_sector] = 512
+  units[:chars] = "bsKkMmGgTtPpEeZzYy"
+  units[:strings] = [ 'bytes', 'sectors',
                       'kilobytes', 'kibibytes', 'megabytes',  'mebibytes',
                       'gigabytes', 'gibibytes', 'terabytes',  'tebibytes',
                       'petabytes', 'pebibytes', 'exabytes',   'ebibytes',
                       'zetabytes', 'zebibytes', 'yottabytes', 'yobibytes' ]
-  units[:factors] = Array.new
-
-  units[:factors][0] = 512
-  1.step(8) do |e|
-    i = (e - 1) * 2 + 1
-    units[:factors][i] = 1024**e
-    units[:factors][i + 1] = 1000**e
-  end
+  units[:factors] = [ 1, units[:bytes_per_sector] ]
+  1.step(8) { |e| units[:factors] += [ 1024**e, 1000**e ] }
   units
 end
 
+def get_index(unit_char, units)
+  unit_char ? units[:chars].index(unit_char) : 1
+end
+
 def check_opts(opts)
   abort "#{$prg} - 3 arguments required!" if opts.length < 3
   abort "#{$prg} - poolsize must be much larger than blocksize" if opts[:poolsize] < opts[:blocksize]
   abort "#{$prg} - maximum number of thin provisioned devices must be > 0" if opts[:maxthins].nil? || opts[:maxthins] == 0
 end
 
-def to_sectors(size, units)
+def to_bytes(size, units)
   a = size.split(/[#{units[:chars]}]/)
   s = size.to_i.to_s
   abort "#{$prg} - only one unit character allowed!" if a.length > 1 || size.length - s.length > 1
   abort "#{$prg} - invalid unit specifier!" if s != a[0]
-  idx = units[:chars].index(size[a[0].length])
-  r = size.to_i * units[:factors][idx] / units[:factors][0]
-  r
+  size.to_i * units[:factors][get_index(size[a[0].length], units)]
 end
 
 def parse_command_line(argv, units)
   opts = {}
 
   os = OptionParser.new do |o|
-    o.banner = "Thin Provisioning Metadata Size Calculator.\nUsage: #{$prg} [opts]"
+    o.banner = "Thin Provisioning Metadata Device Size Calculator.\nUsage: #{$prg} [opts]"
     o.on("-b", "--block-size BLOCKSIZE[#{units[:chars]}]", String,
          "Block size of thin provisioned devices.") do |bs|
-      opts[:blocksize] = to_sectors(bs, units)
+      opts[:blocksize] = to_bytes(bs, units)
     end
-    o.on("-s", "--pool-size SIZE[#{units[:chars]}]", String, "Size of the pool device.") do |ps|
-      opts[:poolsize] = to_sectors(ps, units)
+    o.on("-s", "--pool-size SIZE[#{units[:chars]}]", String, "Size of pool device.") do |ps|
+      opts[:poolsize] = to_bytes(ps, units)
     end
     o.on("-m", "--max-thins #MAXTHINS", Integer, "Maximum sum of all thin devices and snapshots.") do |mt|
       opts[:maxthins] = mt
@@ -96,10 +93,10 @@ def mappings_per_block
 end
 
 def estimated_result(opts, units)
-  idx = opts[:units] ? units[:chars].index(opts[:units]) : 0
+  idx = get_index(opts[:units], units)
   # double-fold # of nodes, because they aren't fully populated in average
-  r = (1.0 + ((opts[:poolsize] / opts[:blocksize] / mappings_per_block) * 2 + opts[:maxthins])) * 8 * units[:factors][0] # in bytes!
-  r /= units[:factors][idx]
+  r = (1.0 + (2 * (opts[:poolsize] / opts[:blocksize] / mappings_per_block) + opts[:maxthins])) * 8 * units[:bytes_per_sector] # in bytes!
+  r /= units[:factors][idx] # in requested unit
   tmp = "%.2f" % r
   if tmp.to_f > 0.0
     r = tmp.to_i.to_f == tmp.to_f ? tmp.to_i : tmp
@@ -113,6 +110,5 @@ end
 
 #----------------------------------------------------------------
 # Main
-
-units = init_units
-puts estimated_result(parse_command_line(ARGV, units), units)
+#
+puts estimated_result(parse_command_line(ARGV, (units = init_units)), units)