diff --git a/billard/tests.py b/billard/tests.py
index 7ce503c..e738093 100644
--- a/billard/tests.py
+++ b/billard/tests.py
@@ -1,3 +1,112 @@
+from datetime import datetime, time
+
 from django.test import TestCase
 
-# Create your tests here.
+from billard.utils import calculate_prize_for, get_prize_for
+
+
+class PrizeCalculationTestCase(TestCase):
+    def calculate_prize_for(self, start, end, pph, expected):
+        self.assertEqual(calculate_prize_for(start, end, pph), expected)
+
+    def test_cpf_1(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 7)
+        pph = 10
+        self.calculate_prize_for(start, end, pph, pph)
+
+    def test_cpf_2(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 6, 30)
+        pph = 10
+        expected = 5
+        self.calculate_prize_for(start, end, pph, expected)
+
+    def test_cpf_3(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 6, 15)
+        pph = 10
+        expected = 2.5
+        self.calculate_prize_for(start, end, pph, expected)
+
+    def test_cpf_4(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 6, 1)
+        pph = 60
+        expected = 1
+        self.calculate_prize_for(start, end, pph, expected)
+
+
+class PrizeGetTestCase(TestCase):
+    def get_prize_for(self, start, end, pph=0, hh_start=None, hh_end=None, pphh=0, expected=(0,0,0)):
+        self.assertEqual(get_prize_for(start, end, pph, hh_start, hh_end, pphh), expected)
+
+    def test_gpf_1(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 7)
+        hh_start = None
+        hh_end = None
+        pph = 10
+        pphh = 5
+        expected = (10, 10, 0)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_2(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 8)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (15, 10, 5)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_3(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 1, 9)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (25, 20, 5)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_4(self):
+        start = datetime(2017, 1, 1, 6)
+        end = datetime(2017, 1, 2, 9)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (260, 250, 10)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_5(self):
+        start = datetime(2017, 1, 1, 7, 30)
+        end = datetime(2017, 1, 1, 8)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (2.5, 0, 2.5)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_6(self):
+        start = datetime(2017, 1, 1, 7, 30)
+        end = datetime(2017, 1, 1, 8, 30)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (7.5, 5, 2.5)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
+
+    def test_gpf_7(self):
+        start = datetime(2017, 1, 1, 6, 30)
+        end = datetime(2017, 1, 1, 7, 30)
+        hh_start = time(7)
+        hh_end = time(8)
+        pph = 10
+        pphh = 5
+        expected = (7.5, 5, 2.5)
+        self.get_prize_for(start, end, pph, hh_start, hh_end, pphh, expected)
\ No newline at end of file
diff --git a/billard/utils.py b/billard/utils.py
index 302bd82..9f8b6f0 100644
--- a/billard/utils.py
+++ b/billard/utils.py
@@ -18,7 +18,7 @@ def get_prize_for(start, end, pph=0, hh_start=None, hh_end=None, pphh=0):
     prize = 0
     prize_normal = 0
     prize_hh = 0
-    if hh_start is not None and hh_end is not None and pphh is not None:
+    if hh_start and hh_end and pphh:
         d = start.date()
         t = start.time()
         end_date = end.date()
@@ -31,35 +31,39 @@ def get_prize_for(start, end, pph=0, hh_start=None, hh_end=None, pphh=0):
                     prize_normal += p
                     break
                 else:
-                    p += calculate_prize_for(start=t, end=hh_start, pph=pph)
+                    p = calculate_prize_for(start=t, end=hh_start, pph=pph)
                     prize += p
                     prize_normal += p
                     t = hh_start
+                    continue
             elif hh_start <= t < hh_end:
                 if end_time < hh_end and d == end_date:
-                    p += calculate_prize_for(start=t, end=end_time, pph=pphh)
+                    p = calculate_prize_for(start=t, end=end_time, pph=pphh)
                     prize += p
                     prize_hh += p
                     break
                 else:
-                    p += calculate_prize_for(start=t, end=hh_end, pph=pphh)
+                    p = calculate_prize_for(start=t, end=hh_end, pph=pphh)
                     prize += p
                     prize_hh += p
                     t = hh_end
+                    continue
             else:
                 if d == end_date:
-                    p += calculate_prize_for(start=t, end=end_time, pph=pph)
+                    p = calculate_prize_for(start=t, end=end_time, pph=pph)
                     prize += p
                     prize_normal += p
                     break
                 else:
-                    p += calculate_prize_for(start=t, end=datetime.strptime('23:59:59', '%H:%M:%S').time(), pph=pph)
+                    p = calculate_prize_for(start=t, end=datetime.strptime('23:59:59', '%H:%M:%S').time(), pph=pph)
                     prize += p
                     prize_normal += p
                     t = datetime.strptime('00:00:00', '%H:%M:%S').time()
                     d = (datetime.combine(d, t) + timedelta(days=1)).date()
+                    continue
     else:
         prize = calculate_prize_for(start=start, end=end, pph=pph)
+        prize_normal = prize
     return prize, prize_normal, prize_hh