The average person uses between 80 gallons to 100 gallons of water per day per household.
So that would be between 2,400 gallons of water per month at 80 gallons of water per day or 3,000 gallons of water per day.
For my house we use around 200 gallons of water per day which includes the lawn watering in the spring and summer and sprinklers running for kids to play in etc.
That also includes the laundry water, shower water, washing dishes, drinking water etc.
My water bill averages around $50.00 per month in the winter months when we are not using the sprinklers and can sometimes go up to $80.00 to $100.00 per month in the summer.
Your water usage will vary as different amounts of people use different amounts of water.