Calculator directory

All Tools

Every published calculator in one place, grouped by the kind of energy question you are solving.

Generator Tools

Estimate generator capacity from running loads and startup surge.

Compare running watts with starting watts for a generator load.

Estimate runtime from fuel on hand and a user-entered consumption rate.

Estimate fuel use from a user-entered consumption rate and operating time.

Convert electrical power to current for DC, single-phase, or three-phase systems.

Convert current into watts for DC, single-phase, or three-phase systems.

Solve for the missing volts, amps, or watts value.

Estimate appliance watts from voltage, current, power factor, and system type.

Calculate daily and period energy use from load and schedule.

Estimate daily, selected-period, and annual electricity cost using an editable rate.

Estimate usable battery runtime from capacity, load, and efficiency.

Estimate nominal battery capacity needed for a target runtime.

Convert amp-hours into stored watt-hours.

Convert watt-hours into amp-hours at a selected voltage.

Estimate charging time with charging efficiency and charger power.

Estimate required solar array size from daily energy, peak sun hours, and system efficiency.

Estimate battery capacity for a daily or backup energy requirement.

Estimate solar charging time from battery capacity, panel power, and charging efficiency.

Estimate continuous inverter rating and surge capability from connected loads.