Water Leak Cost Calculator Formula
Understand the math behind the water leak cost calculator. Each variable explained with a worked example.
Formulas Used
Annual Water Wasted
annual_waste = annual_galAnnual Cost of Leak
annual_cost = annual_gal * water_rate / 1000Daily Waste
daily_waste = daily_galMonthly Cost
monthly_cost = annual_gal * water_rate / 1000 / 12Variables
| Variable | Description | Default |
|---|---|---|
drips_per_min | Drips per Minute(drips) | 10 |
drip_volume_ml | Volume per Drip(mL) | 0.05 |
water_rate | Water Rate(USD/1000 gal) | 5 |
daily_gal | Derived value= drips_per_min * drip_volume_ml * 1440 / 3785.41 | calculated |
annual_gal | Derived value= daily_gal * 365 | calculated |
How It Works
How to Calculate Water Leak Costs
Even a slow drip wastes significant water over time.
Formula
Daily Gallons = Drips/min * mL/drip * 1,440 min/day / 3,785.41 mL/gal
Annual Cost = Daily Gallons * 365 * Rate
Common Leak Rates
Worked Example
A faucet dripping 10 times per minute, 0.05 mL per drip, at $5/1000 gal.
- 01Daily waste: 10 * 0.05 * 1,440 / 3,785.41 = 0.19 gallons
- 02Annual waste: 0.19 * 365 = 69 gallons
- 03Annual cost: 69 * $5 / 1,000 = $0.35
- 04Note: A faster drip or running toilet wastes far more
Frequently Asked Questions
How much water does a dripping faucet waste?
A faucet dripping once per second wastes about 3,000 gallons per year. A faster stream can waste 5-20 gallons per day or more.
How do I detect hidden leaks?
Read your water meter, then avoid using water for 2 hours and read again. Any movement indicates a leak. Also check for damp spots, mold, or unusually high bills.
How much does a running toilet waste?
A running toilet can waste 200 gallons per day or more, adding $30-50 per month to your water bill. Test by putting food coloring in the tank; if it appears in the bowl without flushing, you have a leak.
Ready to run the numbers?
Open Water Leak Cost Calculator