If your water bill suddenly spiked, the cause is almost always a hidden leak or a running toilet — not a billing error. Use the calculator below to estimate how many gallons (and dollars) a leak is wasting, then run the two-minute meter test to confirm it. A silent toilet flapper or an underground supply leak can quietly waste hundreds of gallons a day. When the leak is hidden — underground, in a slab, or behind a wall — our leak detection and pipe repair in Bellevue, WA finds it without tearing up the house.
Pick a likely cause to estimate the waste.
Waste rates are EPA WaterSense figures (sources below); dollar amounts use the rate you enter and are estimates. Your actual rate is on your water bill.
A water bill that jumps with no change in habits is almost always a hidden leak — most often a running or silently leaking toilet, followed by an underground supply-line or slab leak. Rate increases and seasonal irrigation are the next most common causes.
Toilets are the number-one culprit because they can leak silently — a worn flapper lets water trickle from the tank to the bowl around the clock with no sound and no visible overflow. The EPA estimates household leaks waste nearly 10,000 gallons a year, and a single running toilet can waste 200 gallons a day.
If the calculator above points to a hidden leak — or your bill jumped with nothing visible — the next step is the meter test below. It tells you in two minutes whether water is moving when everything is off.
Turn off every water fixture and appliance, then watch your water meter for two minutes. If the meter's flow indicator (the small dial or triangle) moves at all, water is leaving the system somewhere — you have a leak.
Step 1: shut off all taps, the dishwasher, the washing machine, and the ice maker. Step 2: find your water meter (usually in a box near the street or in the garage) and note the reading or watch the low-flow indicator. Step 3: wait two minutes without using any water. If the indicator spins or the reading climbs, water is being used somewhere it shouldn't be.
To confirm a toilet specifically, drop a few drops of food coloring into the tank (not the bowl) and wait 10–15 minutes without flushing. If color appears in the bowl, the flapper is leaking. If the meter still moves with every toilet shut off, the leak is elsewhere — a supply line, slab, or irrigation line — and needs professional leak detection to locate.
A faucet dripping once per second wastes about 3,000 gallons a year; a running toilet can waste 200 gallons a day; and the average home's leaks add up to nearly 10,000 gallons a year. At Eastside water-and-sewer rates, that's real money every month.
The cheap fixes — a flapper, a faucet cartridge, a fill valve — usually pay for themselves within a billing cycle or two. The expensive scenario is the leak you can't see: an underground or under-slab supply line that runs for months before the bill finally forces the issue. The longer it runs, the more it costs in both water and potential structural damage.
Call for professional leak detection when the meter keeps moving after every fixture is off, when you see unexplained damp spots or hear running water in walls or floors, or when the bill stays high after you've fixed the obvious toilets and faucets.
Hidden leaks — slab leaks under the foundation, underground service-line leaks, and in-wall pinhole leaks — can't be found by looking. We locate them with acoustic and pressure equipment and repair only where needed, instead of opening every wall. Older Bellevue neighborhoods on original copper or galvanized supply lines are especially prone to slab and underground leaks.
Ready for a real, written flat-rate quote? These are the services behind the estimates above:
Serial-number formats are decoded from published manufacturer and inspection references. Always confirm against the date on your unit's rating plate.
A bill that doubles overnight is almost always a hidden leak — most often a silently running toilet or an underground/slab supply-line leak — rather than a billing error. Run the meter test above: shut off all water and watch the meter for two minutes. If it moves, you have a leak. Toilets are the most common cause because they leak without any sound.
Most U.S. single-family homes run roughly $40–$80 a month for water and sewer combined, depending on local rates and household size. On the Eastside, combined water-and-sewer rates run higher than the national average. A bill well above your own baseline — not the national average — is the real signal that something changed.
Toilets are the single biggest source of indoor water waste, especially a running or silently leaking one (up to 200 gallons a day). After that: dripping faucets, leaking showerheads, irrigation systems left running, and hidden supply-line leaks. The calculator above estimates the waste for each.
Start with your water utility to rule out a meter or rate change, then call a plumber for leak detection if the meter test shows water moving with everything off. We locate hidden leaks — slab, underground, and in-wall — with acoustic and pressure equipment and repair only where needed.
