diff --git a/tipbot.py b/tipbot.py
index 4333da5..74bfcf4 100644
--- a/tipbot.py
+++ b/tipbot.py
@@ -137,7 +137,7 @@ def AddBalance(link,cmd):
     link.send('usage: !addbalance [<nick>] <amount>')
     return
   try:
-    units = long(float(amount)*coinspecs.atomic_units)
+    units = StringToUnits(amount)
   except Exception,e:
     log_error('AddBalance: error converting amount: %s' % str(e))
     link.send('usage: !addbalance [<nick>] <amount>')
diff --git a/tipbot/betutils.py b/tipbot/betutils.py
index 8c297c3..8ef597f 100644
--- a/tipbot/betutils.py
+++ b/tipbot/betutils.py
@@ -38,10 +38,10 @@ def IsBetValid(link,amount,minbet,maxbet,potential_loss,max_loss,max_loss_ratio)
   if banned:
     return False, reason
   try:
+    units = StringToUnits(amount)
     amount = float(amount)
   except Exception,e:
     return False, "Invalid amount"
-  units=long(amount*coinspecs.atomic_units)
   if units <= 0:
     return False, "Invalid amount"
   if maxbet != None and amount > maxbet:
@@ -315,10 +315,9 @@ def ReserveBalance(link,cmd):
   rbal=GetParam(cmd,1)
   if rbal:
     try:
-      rbal=float(cmd[1])
+      rbal=StringToUnits(cmd[1])
       if rbal < 0:
         raise RuntimeError('negative balance')
-      rbal = long(rbal * coinspecs.atomic_units)
     except Exception,e:
       log_error('SetReserveBalance: invalid balance: %s' % str(e))
       link.send("Invalid balance")
diff --git a/tipbot/modules/blackjack.py b/tipbot/modules/blackjack.py
index 0b12b5c..ae34702 100644
--- a/tipbot/modules/blackjack.py
+++ b/tipbot/modules/blackjack.py
@@ -555,7 +555,7 @@ def Blackjack(link,cmd):
     return
   try:
     amount=float(cmd[1])
-    units=long(amount*coinspecs.atomic_units)
+    units=StringToUnits(cmd[1])
   except Exception,e:
     link.send("%s: usage: !blackjack amount" % link.user.nick)
     return
diff --git a/tipbot/modules/bookie.py b/tipbot/modules/bookie.py
index e587079..f055cc8 100644
--- a/tipbot/modules/bookie.py
+++ b/tipbot/modules/bookie.py
@@ -273,11 +273,10 @@ def Bet(link,cmd):
     link.send('usage: !bet [<event name>] <outcome> <amount>')
     return
   try:
-    amount = float(amount)
+    units = StringToUnits(amount)
   except Exception,e:
     link.send('usage: !bet [<event name>] <outcome> <amount>')
     return
-  units = long(amount*coinspecs.atomic_units)
   if units <= 0:
     link.send("Invalid amount")
     return
diff --git a/tipbot/modules/dice.py b/tipbot/modules/dice.py
index 636da0f..eeae8a3 100644
--- a/tipbot/modules/dice.py
+++ b/tipbot/modules/dice.py
@@ -49,7 +49,7 @@ def Dice(link,cmd):
   identity=link.identity()
   try:
     amount=float(cmd[1])
-    units=long(amount*coinspecs.atomic_units)
+    units=StringToUnits(cmd[1])
     multiplier = float(cmd[2])
     overunder=GetParam(cmd,3)
   except Exception,e:
diff --git a/tipbot/modules/tipping.py b/tipbot/modules/tipping.py
index dd4d994..6257efe 100644
--- a/tipbot/modules/tipping.py
+++ b/tipbot/modules/tipping.py
@@ -63,11 +63,10 @@ def Tip(link,cmd):
   identity=link.identity()
   try:
     who=cmd[1]
-    amount=float(cmd[2])
+    units=StringToUnits(cmd[2])
   except Exception,e:
     link.send("Usage: tip nick amount")
     return
-  units=long(amount*coinspecs.atomic_units)
   if units <= 0:
     link.send("Invalid amount")
     return
@@ -105,6 +104,7 @@ def Rain(link,cmd):
 
   try:
     amount=float(cmd[1])
+    units = StringToUnits(cmd[1])
   except Exception,e:
     link.send("Usage: rain amount [users]")
     return
@@ -122,7 +122,6 @@ def Rain(link,cmd):
   if users != None and users <= 0:
     link.send("Usage: rain amount [users]")
     return
-  units = long(amount * coinspecs.atomic_units)
 
   try:
     account = GetAccount(identity)
@@ -202,6 +201,7 @@ def RainActive(link,cmd):
     link.send("usage: !rainactive <amount> <hours> [<minfrac>]")
     return
   try:
+    units=StringToUnits(amount)
     amount=float(amount)
     if amount <= 0:
       raise RuntimeError("")
@@ -227,8 +227,6 @@ def RainActive(link,cmd):
   else:
     minfrac = 0
 
-  units = long(amount * coinspecs.atomic_units)
-
   try:
     account = GetAccount(link)
     balance = redis_hget("balances",account)
diff --git a/tipbot/modules/withdraw.py b/tipbot/modules/withdraw.py
index 73a3393..8737c1d 100644
--- a/tipbot/modules/withdraw.py
+++ b/tipbot/modules/withdraw.py
@@ -61,10 +61,9 @@ def Withdraw(link,cmd):
   amount = GetParam(cmd,2)
   if amount:
     try:
-      famount=float(amount)
-      if (famount < 0):
+      amount = StringToUnits(amount)
+      if (amount <= 0):
         raise RuntimeError("")
-      amount = long(famount * coinspecs.atomic_units)
       amount += local_withdraw_fee
     except Exception,e:
       link.send("Invalid amount")
diff --git a/tipbot/utils.py b/tipbot/utils.py
index 48106af..da1f350 100644
--- a/tipbot/utils.py
+++ b/tipbot/utils.py
@@ -177,6 +177,13 @@ def TimeToString(seconds):
     return "%.2f millenia" % (seconds / (3600*24*365.25 * 100))
   return "like, forever, dude"
 
+def StringToUnits(s):
+  try:
+    return long(Decimal(s)*long(coinspecs.atomic_units))
+  except Exception,e:
+    log_error('Failed to convert %s to units: %s' % (s,str(e)))
+    raise
+
 def SendJSONRPCCommand(host,port,method,params):
   try:
     http = httplib.HTTPConnection(host,port,timeout=20)