Estimate water consumption from a user-entered flow rate and runtime or a known volume per use. Project recurring use, combine activities, and optionally apply your own water and sewer rates.
Continuous-flow use is flow rate multiplied by duration. Known-volume mode handles cycles and events that do not have a meaningful continuous flow.
Frequency is annualized using 365 days, 52 weeks, 12 months, or the entered yearly count. Daily, weekly, and monthly values are averages derived from the annual result.
volume per event = normalized flow rate × normalized durationannual volume = volume per event × quantity × annual event countannual volume ÷ 12billing quantity × user-entered water ratebilling quantity × user-entered sewer rate, when explicitly enabledduration = target volume ÷ normalized flow rateaffordable billing units = budget ÷ rateA 2 gpm flow for 10 minutes uses 20 gallons. Once daily, that is 7,300 gallons per year and about 608.33 gallons per average month.
Four identical daily 10-minute uses at 2 gpm consume 80 gallons daily and 29,200 gallons annually.
An 8 L/min flow for 5 minutes uses 40 L. Twice daily, that is 80 L per day and 29,200 L (29.2 m³) annually.
A 40-gallon known-volume cycle used five times weekly totals 200 gallons weekly and 10,400 gallons annually under the 52-week convention.
At $6 per 1,000 gallons, 7,300 gallons has an estimated usage charge of $43.80.
A 100-gallon target at 5 gpm permits 20 minutes of runtime.
A $30 budget at $6 per 1,000 gallons represents 5,000 affordable gallons.
CalcRocket does not infer fixture flow, appliance cycle consumption, or household behavior.
Laundry, dishwashing, toilet flushing, and tank refills are often clearer as user-entered volume per event.
A rate per 1,000 gallons must be applied to thousand-gallon units, not to every gallon.
Sewer billing rules differ. It is included only when you explicitly apply the entered sewer rate to all calculated use.
Flow units are normalized to liters per minute with the shared volume and duration converters. A flow rate is never treated as plain volume.
Daily frequency uses 365 days, weekly frequency uses 52 weeks, monthly frequency uses 12 months, and annual frequency uses the entered count. Monthly output is annual usage divided by 12 rather than a hidden 30-day assumption.
Each included activity is calculated independently at full precision. Annual liters are summed before display conversion, and shares refer only to the listed activities.
Rates are user-entered and may be per gallon, 1,000 gallons, liter, 1,000 liters, or cubic meter. Optional fixed monthly charges are shown separately and annualized by multiplying by 12.
Runtime mode divides a target volume by flow. Budget mode divides the entered budget by a positive water rate and converts the result from the selected billing unit.
Multiply flow rate by duration, then apply quantity and recurring frequency.
Multiply gallons per minute by the number of minutes used.
Enter the measured or manufacturer-stated flow and your runtime. No standard shower flow is assumed.
Multiply liters per minute by duration in minutes.
Multiply water per event by the number of events and identical users or fixtures per day.
CalcRocket annualizes the selected frequency and divides by 12 for an average month.
Multiply event volume by annual event count and quantity.
Yes. Enter the known volume per cycle from your own documentation or measurement.
Convert annual use to the selected billing unit and multiply by your entered rate.
Divide gallons by 1,000, then multiply those billing units by the rate.
Yes, but they apply only when you explicitly enable sewer and confirm it applies to all calculated use.
Yes. Multiple Activities mode aggregates up to 20 included rows.
Reverse runtime divides target volume by your entered positive flow rate.
No. It performs arithmetic using the rate you enter and does not fetch live utility data.
No. Enter a measured value or one documented by the fixture manufacturer.