Water suppliers’ statutory service standard level of mains water pressure is 10 metres/head (or one bar). This means there is enough force/pressure to push the water to a height of 10m.
This is measured at the point where the water leaves the water suppliers pipework and enters yours (usually the outside stop valve or property boundary).
As a guide, if you have a suitable single service pipe, the first tap in the home (this is usually the kitchen tap) should be able to fill a 4.5 litre (one gallon) bucket in 30 seconds, with all other taps and appliances turned off. Another way of putting it is enough water pressure to fill a cold water storage cistern in a two storey house roofspace.