Technical toolbox
All calculators.
Choose a tool, check the units and assumptions, and compare the result with the worked example.
Lighting and Luminaire Count Calculator
Estimate luminaire count, average maintained illuminance, connected load and energy use with the lumen method.
Open calculator →Electricity Consumption and Cost Calculator
Use power, quantity and operating time to estimate kWh consumption and cost at your own unit price.
Open calculator →Ohm’s Law: Current and Power Calculator
Calculate current and dissipated power from voltage and resistance for a DC or purely resistive circuit.
Open calculator →kW to Amps Calculator
Calculate current from electrical active input power, voltage and power factor in a single-phase or balanced three-phase system.
Open calculator →Amps to kW Calculator
Estimate active input power from current, voltage and power factor.
Open calculator →Three-Phase Motor Current Calculator
Estimate full-load current from shaft output power, line voltage, efficiency and power factor.
Open calculator →Single-Phase Motor Current Calculator
Estimate single-phase motor current from shaft power, voltage, efficiency and power factor.
Open calculator →Horsepower to kW Converter
Convert mechanical horsepower to kilowatts.
Open calculator →kW to Horsepower Converter
Convert kilowatts to mechanical horsepower.
Open calculator →Voltage Drop Calculator
Estimate resistive cable voltage drop from current, length, conductor area and resistivity.
Open calculator →Cable Area from Voltage Drop
Estimate conductor area required by a chosen voltage-drop target.
Open calculator →Power Factor Calculator
Find the ratio of active power in kW to apparent power in kVA.
Open calculator →Reactive Compensation Estimate
Estimate capacitor reactive power for improving an inductive load’s power factor.
Open calculator →Cable Ampacity Correction
Apply temperature and grouping factors to a manufacturer’s base current rating.
Open calculator →Motor Protection Arithmetic Check
Apply a chosen current factor and show the next listed nominal rating.
Open calculator →BTU/h to kW Converter
Convert heating or cooling capacity from BTU per hour to kilowatts.
Open calculator →kW to kcal/h Converter
Convert thermal power in kilowatts to kilocalories per hour.
Open calculator →Airflow Unit Converter
Convert volumetric airflow from m³/h to m³/s and litres per second.
Open calculator →m³/h to L/s Converter
Convert volumetric flow from cubic metres per hour to litres per second.
Open calculator →L/s to m³/h Converter
Convert litres per second to cubic metres per hour.
Open calculator →Fan Power Calculator
Estimate fan shaft power from volumetric airflow, total pressure and efficiency.
Open calculator →Pump Power Calculator
Estimate pump shaft power for water from flow, head and pump efficiency.
Open calculator →Chilled-Water Flow Calculator
Estimate water flow from cooling capacity and supply/return temperature difference.
Open calculator →Sensible Air Heat Load
Estimate sensible heat transfer from airflow and temperature difference.
Open calculator →Temperature Difference Calculator
Find the absolute difference between two temperatures.
Open calculator →Water-Side Cooling Capacity
Estimate transferred cooling capacity from measured water flow and temperature difference.
Open calculator →Airflow from Sensible Load
Estimate airflow needed to transfer a sensible heat load at a chosen temperature difference.
Open calculator →Pt100 Resistance to Temperature
Estimate temperature from a Pt100 resistance using a linear model.
Open calculator →NTC Resistance to Temperature
Estimate NTC temperature from resistance, reference resistance and beta coefficient.
Open calculator →Frequency to Synchronous Speed
Find synchronous motor speed from supply frequency and pole count.
Open calculator →Synchronous Speed to Frequency
Find frequency corresponding to a synchronous speed and pole count.
Open calculator →BACnet Instance Planning
Combine building, panel and device numbers into a planning identifier.
Open calculator →Modbus Register Offset
Convert a 4xxxx holding-register reference to a zero-based offset.
Open calculator →CIDR Subnet Mask
Calculate the IPv4 mask and address capacity for a CIDR prefix.
Open calculator →RS-485 Distance Planning Estimate
Show a rough distance estimate for a selected baud rate.
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