1Φ
Electrical · Power
Open kW to amps — single-phase calculatorkW to amps — single-phase
Convert electrical input power in kW to line current for a single-phase circuit using voltage and power factor.
FreeFormula shownNo account
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3Φ
Electrical · Power
Open kW to amps — three-phase calculatorkW to amps — three-phase
Convert electrical input power in kW to line current for a balanced three-phase load using line-to-line voltage and power factor.
FreeFormula shownNo account
A→kW
Electrical · Power
Open Amps to kW calculatorAmps to kW
Convert current to real power in kW for single-phase or balanced three-phase systems using voltage and power factor.
FreeFormula shownNo account
kVA→A
Electrical · Power
Open kVA to amps calculatorkVA to amps
Convert apparent power in kVA to line current for single-phase or balanced three-phase systems.
FreeFormula shownNo account
A→kVA
Electrical · Power
Open Amps to kVA calculatorAmps to kVA
Convert current to apparent power in kVA for single-phase or balanced three-phase systems.
FreeFormula shownNo account
PF
Electrical · Power
Open kW / kVA / kVAr / power factor calculatorkW / kVA / kVAr / power factor
Complete the power triangle from kW and power factor, kVA and power factor, or kW and kVA.
FreeFormula shownNo account
Ω
Electrical · Power
Open Ohm's law calculatorOhm's law
Calculate voltage, current, resistance and power from any supported pair of known electrical values.
FreeFormula shownNo account
TX
Electrical · Power
Open Transformer current calculatorTransformer current
Calculate primary and secondary full-load current from transformer kVA rating and winding voltages.
FreeFormula shownNo account
GEN
Electrical · Power
Open Generator current calculatorGenerator current
Convert a generator rating in kVA or kW to full-load line current for single-phase or balanced three-phase output.
FreeFormula shownNo account
Q
Mechanical / HVAC · Heating
Open Heat loss — U × A × ΔT calculatorHeat loss — U × A × ΔT
Calculate steady-state fabric heat transfer through one building element from U-value, area and temperature difference.
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L/s
Mechanical / HVAC · Water
Open Heating / chilled-water flow calculatorHeating / chilled-water flow
Calculate mass and volume flow from thermal duty, flow/return temperatures and user-entered fluid properties.
FreeFormula shownNo account
ACH
Mechanical / HVAC · Airflow
Open Air changes and airflow calculatorAir changes and airflow
Calculate required airflow from a chosen air-change rate or determine air changes from airflow and room volume.
FreeFormula shownNo account
DUCT
Mechanical / HVAC · Airflow
Open Duct size from airflow and velocity calculatorDuct size from airflow and velocity
Calculate theoretical circular diameter or rectangular dimensions from airflow and target air velocity.
FreeFormula shownNo account
v
Mechanical / HVAC · Water
Open Pipe velocity calculatorPipe velocity
Calculate fluid velocity from volume flow rate and actual pipe internal diameter.
FreeFormula shownNo account
PUMP
Mechanical / HVAC · Pumps
Open Pump hydraulic power calculatorPump hydraulic power
Calculate hydraulic power and estimated shaft power from flow, head or pressure difference, density and pump efficiency.
FreeFormula shownNo account
DHW
Public health / Plumbing · Water
Open DHW heat-up time calculatorDHW heat-up time
Estimate the time and useful heat required to raise a stored water volume between two temperatures.
FreeFormula shownNo account
MIX
Public health / Plumbing · Water
Open Mixing temperature calculatorMixing temperature
Calculate mixed-water temperature from two amounts or find hot/cold proportions for a target temperature.
FreeFormula shownNo account
1:n
Public health / Plumbing · Drainage
Open Drain fall / gradient / levels calculatorDrain fall / gradient / levels
Calculate fall from length and gradient, gradient from length and fall, or an end level from a starting level.
FreeFormula shownNo account
RAIN
Public health / Plumbing · Drainage
Open Rainwater runoff calculatorRainwater runoff
Calculate roof runoff from effective area, user-entered rainfall intensity and runoff coefficient.
FreeFormula shownNo account
lx
Electrical · Lighting
Open Lux / lumen preliminary calculation calculatorLux / lumen preliminary calculation
Use the lumen method to estimate average illuminance or preliminary lamp lumens required.
FreeFormula shownNo account
↔
General · Conversions
Open General MEP unit converter calculatorGeneral MEP unit converter
Convert common building-services units for power, energy, airflow, water flow, pressure, temperature, length, area, volume, velocity and illuminance.
FreeFormula shownNo account
ΔV
Electrical · Cables
Open Voltage drop calculatorVoltage drop
Calculate circuit voltage drop using user-entered mV/A/m cable data, current, route length and upstream allowance.
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