How to calculate batting strike rate in cricket

Strike Rate is the total number of runs a batsman will score if he faces 100 deliveries, at the current rate.
It is calculated by the runs scored by batsman divided by the number of balls he faced multiplied by 100.

i.e. Strike rate =  ( Runs scored / No.of balls faced ) * 100

Example :
Sachin Tendulkar scored 93 runs in 89 balls
Strike rate = ( 93 / 89 ) * 100 = 104.49
Strike rate is 104.49

How to calculate net run rate in cricket

Net Run Rate (NRR) is really quite simple to calculate.
Net run rate = (Total runs scored / Total overs faced) - ( Total runs conceded / Total overs bowled )

Example :

For (India)

Against australia , 276/8 in 50 overs
Against West Indies , 288/6 in 48.5 overs
Against Ireland , 187/4 in 37.4 overs

Against

Teams opposing India scored

Australia , 277/7 in 49.4 overs
West Indies , 284 all out in 49.2 overs (If team is all out consider full quota)
Ireland , 186 all out in 42.3 overs

NRR = ( (276+288+187) / (50+48.5+37.4) ) - ( (277+284+186) / (49.4+49.2+42.3) )
NRR = ( 751 / 136.3 ) - ( 747 / 49.4+50+50 )
NRR = ( 5.50 ) - ( 4.99 ) = 0.51

Net Run rate for team india is +0.51

How to calculate run rate in cricket

Case 1 : Basically run rate is calculated by dividing runs scored to number of overs.
  Run rate = Total runs / No.of Overs
  Example : 234 runs in 50 overs
  Run rate = 234 / 50 . Run rate is 4.68 per over

Case 2 : If overs is not an integer (consider 23.4 overs) , then convert into no.of balls
  Run rate = ( Total runs / No.of Balls ) * 6
  Example : 132 runs in 23.4 overs
  23.4 overs i.e. 142 balls (23*6)+4 balls
  Run rate = (132 / 142) * 6 . Run rate is 5.57 per over