Estimate well-pump electricity from running time and power
A water well pump uses electricity while its motor operates, and some control equipment also draws standby power when the motor is off. The operating cost depends on electrical input, actual accumulated run hours and the variable price of electricity. A motor's advertised horsepower does not provide a complete measurement of electrical consumption because motor efficiency, pressure, head and operating conditions matter. Whenever possible, use a measured running-watt figure or an appropriate manufacturer's electrical-input specification.
The daily hours field represents the accumulated time the pump actually runs over a typical day, not the number of hours when household water is available. A pump that runs for five minutes each hour may accumulate only two hours of operation over a day. Pressure tank size, leaks, irrigation demand and control settings can change that duty cycle. The separate standby field applies only to time outside the entered running hours, avoiding counting two power states simultaneously.
Pump energy and billing formulas
Standby energy per day (kWh) = standby watts × (24 − run hours) ÷ 1,000
Period energy (kWh) = (running + standby daily kWh) × billing days
Variable electricity charge = period kWh × rate per kWh
Example: a pump with three hours of daily operation
A pump drawing 1,000 watts for three hours each day uses 3.00 kWh for motor operation. With 5 watts of standby draw during the other 21 hours, controls add 0.105 kWh. Total modeled daily use is 3.105 kWh, or 93.15 kWh for a 30-day period. At a hypothetical $0.18 per kWh, the variable charge for that period is $16.77.
The rate is entered by the user rather than taken from a regional price table. Utility service charges, demand charges, taxes, pumping changes through the seasons and variable-speed drive behavior are not independently modeled.
Find more reliable input measurements
If pump operation is unusually costly, verify whether the assumed daily running hours resemble actual controller logs or meter measurements. A cycling or continuously running pump may indicate a leak, a pressure-control problem or changed groundwater conditions, but an electricity estimate cannot diagnose the equipment. Pump repair and electrical safety should be assessed by qualified professionals.
To compare two pump options, enter each model's expected input watts and use the same daily pumping task and electricity price. It would be misleading to compare equal running times when different pumps deliver different water volumes at the installed total dynamic head. Real savings should be evaluated against equivalent delivered water and actual duty cycle.
Well-pump operating cost questions
Can I use the horsepower printed on the motor?
Horsepower normally describes rated mechanical output, not the exact electrical input. Obtain measured watts or the manufacturer's input-power data at relevant operating conditions to calculate kilowatt-hours accurately.
Why include standby power separately?
Some pump controllers consume electricity while the motor is idle. The calculator applies standby watts only during the remaining hours of the day, so motor runtime and idle time do not overlap.
Is the calculated amount my complete utility bill?
No. It describes modeled pump-related variable energy charges using your entered rate. Other home loads, fixed service fees, tiered tariffs and applicable taxes are excluded.