diff --git a/kbps.py b/kbps.py
index 2c74a16..ed9ba74 100644
--- a/kbps.py
+++ b/kbps.py
@@ -11,54 +11,41 @@ import argparse
 import sys
 
 from voussoirkit import bytestring
-
-def hms_s(hms):
-    hms = hms.split(':')
-    seconds = 0
-    if len(hms) == 3:
-        seconds += int(hms[0])*3600
-        hms.pop(0)
-    if len(hms) == 2:
-        seconds += int(hms[0])*60
-        hms.pop(0)
-    if len(hms) == 1:
-        seconds += int(hms[0])
-    return seconds
-
-def s_hms(s):
-    (minutes, seconds) = divmod(s, 60)
-    (hours, minutes) = divmod(minutes, 60)
-    return '%02d:%02d:%02d' % (hours, minutes, seconds)
+from voussoirkit import hms
 
 def kbps(time=None, size=None, kbps=None):
     if [time, size, kbps].count(None) != 1:
-        raise ValueError('Incorrect number of unknowns')
-
-    if size is None:
-        seconds = hms_s(time)
-        kibs = int(kbps) / 8
-        size = kibs * 1024
-        size *= seconds
-        out = bytestring.bytestring(size)
-        return out
+        raise ValueError('Incorrect number of unknowns.')
 
     if time is None:
         size = bytestring.parsebytes(size)
         kilobits = size / 128
         time = kilobits / int(kbps)
-        return s_hms(time)
+        return time
+
+    if size is None:
+        seconds = hms.hms_to_seconds(time)
+        kibs = int(kbps) / 8
+        size = kibs * 1024
+        size *= seconds
+        return size
 
     if kbps is None:
-        seconds = hms_s(time)
+        seconds = hms.hms_to_seconds(time)
         size = bytestring.parsebytes(size)
         kibs = size / 1024
         kilobits = kibs * 8
         kbps = kilobits / seconds
-        kbps = '%d kbps' % int(round(kbps))
         return kbps
 
-def example_argparse(args):
-    print(kbps(time=args.time, size=args.size, kbps=args.kbps))
+def kbps_argparse(args):
+    result = kbps(time=args.time, size=args.size, kbps=args.kbps)
+    if args.time is None:
+        print(hms.seconds_to_hms(time))
+    if args.size is None:
+        print(bytestring.bytestring(size))
+    if args.kbps is None:
+        print('%d kbps' % round(result))
 
 def main(argv):
     parser = argparse.ArgumentParser()
@@ -66,7 +53,7 @@ def main(argv):
     parser.add_argument('-t', '--time', dest='time', default=None)
     parser.add_argument('-s', '--size', dest='size', default=None)
     parser.add_argument('-k', '--kbps', dest='kbps', default=None)
-    parser.set_defaults(func=example_argparse)
+    parser.set_defaults(func=kbps_argparse)
 
     args = parser.parse_args(argv)
     return args.func(args)