How to read a water meter
Read the main row of numbers from left to right, zeros included. That is cubic metres, and each one is 1,000 litres. The red numbers after them are smaller amounts: your bill ignores them, but they are the first to move when there is a leak.
Find your water meter
Most meters sit outside, under a small metal or plastic cover in the pavement or front garden, close to your boundary. That is often where the outside stop tap is too.
Some are indoors on the pipe where it comes into the house, usually near the internal stop tap under the kitchen sink or in a downstairs toilet. In flats, meters are often in a shared cupboard or a box on an outside wall.
Opening an outside cover
Lift the lid with a flat screwdriver. Underneath there may be a foam or polystyrene disc that stops the meter freezing, so put it back when you have finished. If the cover is in the road, is heavy, or will not move, leave it and ask your water company to read the meter for you.
Read the numbers
The main numbers count cubic metres. On most meters they are black on white, and on some they are white on black. The red numbers, or small red dials, are the part of a cubic metre after the point.
Type what you see and we will turn it into litres, and into the figure to give your water company.
Include any zeros at the front. Leave the red numbers empty if your meter has none.
Your reading in litres will appear here.
What one unit on your meter means
One unit is one cubic metre: 1,000 litres of water, or about twelve full baths. Water companies charge per cubic metre, and the sewerage charge on a metered bill is usually worked out from the same reading.
Your bill takes the reading at the start of the billing period away from the reading at the end. The difference is the number of cubic metres you pay for.
This reading − last reading = cubic metres used
Divide that by the days between the readings and multiply by 1,000, and you have litres a day. The water usage calculator does it for you and compares the result with typical use.
Check the serial number matches your bill
The long number printed on the meter body, often above or below the dials, is its serial number. Your bill shows the serial number of the meter you are being charged for.
If they do not match, you may be billed for someone else’s meter. It happens on rare occasions, most often in flats or where neighbours share a supply pipe. Tell your water company straight away and send them a photo of the meter.
Digital and smart meters
A digital meter shows the reading on a small screen. Read the digits before the decimal point for your bill, and note the ones after it for a leak test. Some screens stay blank until you press a button or cover a light sensor with your hand.
Smart meters send readings to your water company, and some companies let you see your use online. If yours shows use by the hour, a figure that never drops to zero in the small hours is a sign water is escaping.
Use your meter to check for a leak
With every tap and appliance off, the red numbers and the little star wheel on the dial should stay still. If they creep, water is getting past the meter.
The guided test times it for you and works out how many litres an hour are escaping.
Meter moving with everything off?
A meter that keeps turning when nothing is on means water is escaping somewhere after it. If you cannot find where, ADI Leak Detection can trace it.
ADI Leak Detection traces hidden leaks on water pipes with tracer gas, acoustic listening and thermal imaging. Their methods are chosen to avoid damage wherever possible, and they usually repair the leak on the same day where they can.
- 25 engineers
- Around 5,000 jobs a year
- England, Scotland and Wales
- Rated 4.7 on Trustpilot
ADI figures September 2026. Trustpilot 1,624 reviews, checked 25 September 2026.