Dripping Faucet Cost Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/8/2026
A faucet dripping at 60 drips per minute (about 1 drip per second) wastes nearly 6,900 liters of water per year, about €30 at the average national rate, based on US Environmental Protection Agency (EPA) benchmarks.
Explanation
A leak that seems insignificant drop by drop actually represents a substantial volume of water once accumulated over a full year — the same perspective effect exploited by our daily coffee cost calculator, applied here to water rather than a voluntary expense. This calculator relies on a benchmark documented by the US Environmental Protection Agency (EPA, WaterSense program): a faucet dripping at a rate of one drip per second (60 drips per minute) wastes more than 3,000 gallons of water per year, or about 5 gallons (19 liters) per day. This benchmark is deliberately preferred over the theoretical conversion 'one drip = 0.05 mL' found on many sites, because a real faucet drip, held back by surface tension around the spout before detaching, is noticeably bigger than a pure laboratory water drop — using the theoretical value would underestimate actual waste by a factor of about 4. The calculation remains linear: doubling the number of drips per minute doubles the volume lost and the associated cost. For a bigger leak (a continuous trickle rather than distinct drops), the volume lost can reach several dozen cubic meters per year, well beyond what this calculator, designed for a drip-by-drip leak, can correctly estimate.
Example: a faucet dripping at 60 drips per minute
Inputs
Drips per minute: 60. Water price: €4.34/m³.
Calculation
Annual volume = 60 × 115.14 ≈ 6,908 liters. Annual cost = (6,908 ÷ 1,000) × 4.34 ≈ €29.98.
Result
This leak wastes about 6,908 liters of water per year, for a cost of about €30.
Frequently asked questions
Why not use the conversion 'one drip = 0.05 mL'?
Because that theoretical value corresponds to a pure water drop falling in a lab, not a real faucet drip. Around a faucet spout, surface tension holds the water longer before it detaches, forming a noticeably bigger drop. Using the theoretical value would underestimate the actual volume lost by a factor of about 4, once cross-checked with the US Environmental Protection Agency's (EPA) empirical measurements.
How do I estimate the number of drips per minute from my faucet?
The simplest way is to count directly: time 30 seconds with a watch and count the number of drips that fall, then multiply by 2 to get the number of drips per minute. A rate of about one drip per second (60 drips/minute) is a common leak benchmark, often cited in plumbing guides.
What if the leak is a continuous trickle rather than distinct drops?
This calculator is designed for a drip-by-drip leak, not a continuous trickle, whose flow is better measured in milliliters or liters per minute. For that case, our volumetric flow rate calculator lets you estimate a volume from a directly measured flow rate (for example with a graduated container and a stopwatch).