diff --git a/tools/python/city_radius.py b/tools/python/city_radius.py
index 274149da56..037c3148bb 100644
--- a/tools/python/city_radius.py
+++ b/tools/python/city_radius.py
@@ -42,7 +42,7 @@ def load_data(path):
     print "Cities count: %d" % len(cities)
 
 def formula(popul, base = 32, mult = 0.5):
-    return math.exp(math.log(popul, base)) * mult
+    return math.pow(popul, 1 / base) * mult
 
 def avgDistance(approx, data):
     dist = 0
@@ -50,7 +50,7 @@ def avgDistance(approx, data):
         dist += math.fabs(approx[x] - data[x])
     return dist / float(len(data))  
 
-def findBest(popul, data, minBase = 5, maxBase = 100, stepBase = 0.1, minMult = 0.01, maxMult = 1, stepMult = 0.01):
+def findBest(popul, data, minBase = 1, maxBase = 100, stepBase = 0.1, minMult = 0.01, maxMult = 1, stepMult = 0.01):
 
     # try to find best parameters
     base = minBase