Annual Water Usage Calculator
Estimate your annual water consumption in gallons. Enter daily usage to project yearly totals for budgeting, conservation planning, and system sizing.
Free Water Calculators
26 toolsWater usage, bill, conservation, rainwater harvesting, and filtration calculators. Browse our free water tools below — no sign-up required.
Cistern Sizing Calculator
Size a rainwater cistern based on daily demand and the longest expected dry spell. Calculate the tank volume needed to bridge gaps between rain events.
Daily Water Usage Calculator
Calculate your daily household water usage in gallons. Enter fixture types, flow rates, and usage minutes to estimate total daily water consumption.
Drip vs Sprinkler Water Use Calculator
Compare water usage between drip irrigation and sprinkler systems. See how much water and money you can save by switching to drip.
Dual-Flush Toilet Savings Calculator
Estimate annual water and cost savings from a dual-flush toilet. Calculate the blended GPF reduction based on liquid and solid flush ratios.
Greywater Reuse Potential Calculator
Estimate how many gallons of greywater you can capture and reuse from showers, laundry, and sinks for irrigation and toilet flushing.
Hot Water Usage Calculator
Estimate your daily hot water consumption by fixture. Enter shower, faucet, dishwasher, and laundry usage to calculate total hot water demand.
Irrigation Water Budget Calculator
Calculate your weekly irrigation water budget based on landscape area, evapotranspiration rate, crop factor, and system efficiency.
Lawn Water Need Calculator
Calculate how many gallons per week your lawn needs based on square footage and irrigation efficiency. Apply the 1-inch-per-week rule accurately.
Low-Flow Faucet Savings Calculator
Calculate annual water and cost savings from installing low-flow faucet aerators. Compare old and new GPM to quantify your conservation gains.
Low-Flow Showerhead Savings Calculator
Calculate annual water and cost savings from switching to a low-flow showerhead. Compare old and new GPM ratings to see your savings.
Low-Flow Toilet Savings Calculator
Calculate annual water and cost savings from upgrading to a low-flow or high-efficiency toilet. Compare gallons per flush to see your savings.
Monthly Water Usage Calculator
Estimate your monthly water consumption in gallons. Enter your daily water usage to see total monthly gallons and compare against averages.
Pool Water Cost Calculator
Calculate the cost to fill and maintain a swimming pool. Estimate initial fill cost plus annual water expenses for top-offs and maintenance.
Rain Barrel Sizing Calculator
Determine how many rain barrels you need based on target collection volume and barrel capacity. Size your system for optimal rainwater storage.
Reverse Osmosis System Cost Calculator
Calculate the annual operating cost of a reverse osmosis system including membrane replacements, pre/post filters, wasted water, and electricity.
Virtual Water Calculator
Calculate the total virtual water in your daily consumption of food, beverages, and goods. Understand the hidden water cost of your lifestyle.
Water Bill Estimator Calculator
Estimate your total water bill including base charges, volume charges, sewer fees, and taxes. Get a complete breakdown of all line items.
Water Conservation Savings Calculator
Calculate the total water and dollar savings from adopting multiple conservation measures. Combine low-flow fixtures, efficient irrigation, and behavioral changes.
Water Cost Calculator
Calculate the cost of water based on volume and your utility rate. Enter gallons or cubic feet and price per unit to find your total water cost.
Water Filter Cost Calculator
Calculate the annual cost of a home water filtration system including filter replacements, system amortization, and per-gallon cost vs bottled water.
Water Footprint (Diet) Calculator
Estimate the water footprint of your diet based on food types and quantities. See how many gallons of water are embedded in your daily meals.
Water Footprint (Product) Calculator
Estimate the virtual water embedded in everyday products. Discover how much water it takes to produce clothing, electronics, paper, and more.
Water Heater Energy Calculator
Calculate the energy cost to heat water. Enter gallons, temperature rise, and heater efficiency to find kWh or therms and total cost.
Water Softener Cost Calculator
Calculate the annual operating cost of a water softener including salt, regeneration water, electricity, and system amortization.
Well Water Testing Cost Calculator
Estimate the total cost of private well water testing based on the number and types of tests required. Plan your annual testing budget.