diff --git a/clockface/clockface.go b/clockface/clockface.go
index 745765b..01caa3e 100644
--- a/clockface/clockface.go
+++ b/clockface/clockface.go
@@ -21,6 +21,15 @@ const (
 	clockCentreY     = 150
 )
 
+const (
+	secondsInHalfClock = 30
+	secondsInClock     = 2 * secondsInHalfClock
+	minutesInHalfClock = 30
+	minutesInClock     = 2 * minutesInHalfClock
+	hoursInHalfClock   = 6
+	hoursInClock       = 2 * hoursInHalfClock
+)
+
 const svgStart = `<?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
 <svg xmlns="http://www.w3.org/2000/svg"
@@ -73,7 +82,7 @@ func makeHand(w io.Writer, length float64, p Point) {
 }
 
 func hoursInRadians(t time.Time) float64 {
-	return (minutesInRadians(t) / 12) + math.Pi/(6/float64(t.Hour()%12))
+	return (minutesInRadians(t) / hoursInClock) + math.Pi/(hoursInHalfClock/float64(t.Hour()%hoursInClock))
 }
 
 func hourHandPoint(t time.Time) Point {
@@ -81,7 +90,7 @@ func hourHandPoint(t time.Time) Point {
 }
 
 func minutesInRadians(t time.Time) float64 {
-	return (secondsInRadians(t) / 60) + math.Pi/(30/float64(t.Minute()))
+	return (secondsInRadians(t) / minutesInClock) + math.Pi/(minutesInHalfClock/float64(t.Minute()))
 }
 
 func minuteHandPoint(t time.Time) Point {
@@ -89,7 +98,7 @@ func minuteHandPoint(t time.Time) Point {
 }
 
 func secondsInRadians(t time.Time) float64 {
-	return math.Pi / (30 / float64(t.Second()))
+	return math.Pi / (secondsInHalfClock / float64(t.Second()))
 }
 
 func secondHandPoint(t time.Time) Point {