How to use this calculator
Enter the number of gallons on your water meter or last bill, your utility's water rate and sewer rate per 1,000 gallons, any flat monthly service fee, and your household size. Click Calculate to see your estimated monthly bill, annual cost, cost per person, and effective rate per gallon. Click Clear to reset all fields to their defaults.
The formula
U.S. water utilities almost universally bill this way: a flat base charge plus a volumetric rate applied to metered usage, typically priced per 1,000 gallons (sometimes per CCF, where 1 CCF ≈ 748 gallons). This calculator applies that formula directly:
Monthly Bill = (Usage ÷ 1,000) × (Water Rate + Sewer Rate) + Fixed FeeAnnual cost is simply the monthly bill multiplied by 12 (assuming steady usage), and the effective rate divides the total bill by the gallons used to show your true average cost per gallon, including the fixed fee.
Understanding the inputs
Monthly usage comes straight off your water meter or the "usage" line of a recent bill. Water rate and sewer rate are the volumetric charges your utility lists per 1,000 gallons — enter sewer as 0 if it's billed separately or you're on a septic system. The fixed service fee is the flat charge that appears regardless of usage (sometimes called a "base charge" or "meter fee"). Household size is only used to split the bill evenly per person and does not affect the total.
Interpreting the results
The monthly and annual figures are your estimated total spend at these rates. Cost per person helps compare against household budgeting benchmarks, while the effective rate (in cents per gallon) is useful for comparing your true tap water cost against alternatives like bottled or filtered water. Because rates are often tiered (higher usage can trigger a higher per-gallon price), this calculator assumes a single flat rate across all usage — check your bill if your utility uses tiered pricing.