Drip Leak Water Waste Calculator
Find out how much water a dripping faucet wastes per year and what it costs you. Use this whenever you spot a slow leak to make the case for a quick repair.
About this calculator
A dripping tap wastes far more water than it appears to. The annual cost formula is: Annual Cost = dripsPerMinute × dropSize × 525,600 × waterCost ÷ 1,000,000. Here, 525,600 is the number of minutes in a year (365 × 24 × 60). Drop size is measured in microlitres (µL); a standard drip is approximately 50 µL. Multiplying drips per minute by drop size gives µL/min, and multiplying by 525,600 converts to total µL per year. Dividing by 1,000,000 converts µL to litres, and multiplying by water cost (in $/m³, where 1 m³ = 1,000 L) yields the annual expenditure. Even a slow drip of 10 drips/min at 50 µL wastes over 260 litres per year.
How to use
Say your faucet drips at 30 drips per minute, each drop is 50 µL, and your water costs $1.50/m³. Annual waste in litres = 30 × 50 × 525,600 ÷ 1,000,000 = 788,400,000 ÷ 1,000,000 = 788.4 litres. Annual cost = 788.4 × $1.50 ÷ 1,000 = $1.18. While the direct cost seems small, that same leak wastes nearly 800 litres of treated drinking water — and multiple dripping fixtures add up quickly across a household.
Frequently asked questions
How much water does a dripping faucet waste per year?
A faucet dripping at just 10 drips per minute — barely noticeable — wastes approximately 263 litres per year assuming a standard 50 µL drop size. At 60 drips per minute (a slow but steady stream), waste climbs to over 1,500 litres annually. Across an average home with multiple fixtures, unrepaired leaks can account for 5–10% of total household water consumption, according to water utility estimates.
How do I measure how many drips per minute my faucet is leaking?
Place a measuring cup under the drip for exactly one minute and count the drops, or measure the collected volume. Alternatively, time how long it takes to fill a known volume — for example, if 100 mL collects in 2 minutes, you can back-calculate drip rate using your drop size. A standard kitchen or bathroom drip produces drops of roughly 50 µL (0.05 mL), so 100 mL in 2 minutes equals about 1,000 drops/min — which would indicate more of a trickle than a drip.
Is it worth fixing a slowly dripping faucet to save money?
The direct water-cost savings from a single slow drip are often under $5 per year, so purely financial ROI can be modest. However, the environmental argument is stronger — hundreds of litres of treated, pressurised drinking water are wasted for no benefit. Additionally, persistent drips can erode washers, damage sink basins, and eventually worsen into more costly leaks. A simple washer replacement typically costs under $5 in parts and prevents compounding damage.