Electrical Calculation formula
Volt -V
Volt definition
Volt is the electrical unit of voltage or potential difference (symbol: V).
One Volt is defined as energy consumption of one joule per electric charge of one
coulomb.
1V = 1J/C
One volt is equal to current of 1 amp times resistance of 1 ohm:
1V = 1A • 1Ω
Alessandro Volta
The Volt unit is named after Alessandro Volta, an Italian physicist who invented
an electric battery.
Volts to watts conversion
The power in watts (W) is equal to the voltage in volts (V) times the current in
amps (A):
watts (W) = volts (V) × amps (A)
Volts to amps conversion
The current in amps (A) is equal to the voltage in volts (V) divided by the resistance
in ohms (Ω):
amps (A) = volts (V) / ohms(Ω)
The current in amps (A) is equal to the power in watts (W) divided by the voltage
in volts (V):
amps (A) = watts (W) / volts (V)
Ampere -I
Ampere definition
Ampere or amp (symbol: A) is the unit of electrical current.
The Ampere unit is named after Andre-Marie Ampere, from France.
One Ampere is defined as the current that flows with electric charge of one Coulomb
per second.
1 A = 1 C/s
Ampere meter
Ampere meter or ammeter is an electrical instrument that is used to measure electrical
current in amperes.
When we want to measure the electrical current on the load, the ampere-meter is
connected in series to the load.
The resistance of the ampere-meter is near zero, so it will not affect the measured
circuit.
How to convert amps to kilo amps (kA)
The current I in kilo amperes (mA) is equal to the current I in amperes (A) times
1000:
I(kA) = I(A) • 1000
How to convert amps to watts (W)
The power P in watts (W) is equal to the current I in amps (A) times the voltage
V in volts (V):
P(W) = I(A) • V(V)
How to convert amps to volts (V)
The voltage V in volts (V) is equal to the power P in watts (W) divided by the current
I in amperes (A):
V(V) = P(W) / I(A)
The voltage V in volts (V) is equal to the current I in amperes (A) times the resistance
R in ohms (Ω):
V(V) = I(A) • R(Ω)
How to convert amps to ohms (Ω)
The resistance R in ohms (Ω) is equal to the voltage V in volts (V) divided by the
current I in amperes (A): R(Ω) = V(V) / I(A)
How to convert amps to kilowatts (kW)
The power P in kilowatts (kW) is equal to the current I in amps (A) times the voltage
V in volts (V) divided by 1000:
P(kW) = I(A) • V(V) / 1000
How to convert amps to kilovolt-ampere (kVA)
The apparent power S in kilovolt-amps (kVA) is equal to RMS current IRMS in amps
(A), times the RMS voltage VRMS in volts (V), divided by 1000:
S(kVA) = IRMS(A) • VRMS(V) / 1000
Watt (W)
Watt definition
Watt is the unit of power (symbol: W).
The watt unit is named after James Watt, the inventor of the steam engine.
One watt is defined as the energy consumption rate of one joule per second.
1W = 1J / 1s
One watt is also defined as the current flow of one ampere with voltage of one volt.
1W = 1V × 1A
How to convert watts to kilowatts
The power P in kilowatts (kW) is equal to the power P in watts (W) divided by 1000:
P(kW) = P(W) / 1000
How to convert watts to amps
The current I in ampers (A) is equal to the power P in watts (W) divided by the
voltage V in volts (V):
I(A) = P(W) / V(V)
How to convert watts to volts
The voltage V in volts (V) is equal to the power P in watts (W) divided by the current
I in ampers (A):
V(V) = P(W) / I(A)
How to convert watts to horsepower
P(HP) = P(W) / 746
How to convert watts to kVA
The real power P in watts (W) is equal to 1000 times the apparent power S in kilo-volt-amperes
(kVA) times the power factor (PF) or cosine of the phase angle φ:
P(W) = 1000 • S(kVA) • PF = 1000 • S(kVA) • cos φ
How to convert watts to VA
The real power P in watts (W) is equal to the apparent power S in volt-amperes (VA)
times the power factor (PF) or cosine of the phase angle φ:
P(W) = S(VA) • PF = S(VA) • cos φ
Farad (F)
Farad is the unit of capacitance. It is named after Michael Faraday.
The farad measures how much electric charge is accumulated on the capacitor.
1 farad is the capacitance of a capacitor that has charge of 1 coulomb when applied
voltage drop of 1 volt
1F = 1C / 1V
What is kilowatt (kW)?
Kilowatt (symbol: kW) is a unit of electric power.
Kilowatt definition
One kilowatt (kW) is equal to 1000 watts (W):
1kW = 1000W
One kilowatt is defined as energy consumption of 1000 joules for 1 second:
1kW = 1000J / 1s
One kilowatt is equal to 1000000 milliwatts:
1kW = 1000000mW
What is kilowatt-hour (kWh)
Kilowatt-hour definition
Kilowatt-hour is an energy unit (symbol kWh or kW•h).
One kilowatt-hour is defined as the energy consumed by power consumption of 1kW
during 1 hour:
1 kWh = 1kW • 1h
One kilowatt-hour is equal to 3.6•106 joules: 1 kWh = 3.6•106 J The energy E in
kilowatt-hour (kWh) is equal to the power P in kilowatts (kW), times the time t
in hours (h).
E(kWh) = P(kW) • t(h)
Kilowatt-hour example
For example what is the energy consumed when consuming 2kW for 3 hours? Solution:
E(kWh) = 2kW • 3h = 6kWh
Kilowatt examples
Example #1
What is the power consumption in kW when energy of 30000 joules was released during
10 seconds?
Solution: P(kW) = 30000J / 10s / 1000 = 3kW
Example #2 What is the power consumption when consuming 6kWh for 3 hours? Solution:
P(kW) = 6kWh / 3h = 2kW
kWh meter
kWh meter is the electric meter that measures the amount of electrical energy in
kWh that was consumed in the house. The kWh meter has a counter display that counts
units of kilowatt-hour (kWh). The energy consumption is calculated by calculating
the difference of the counter's reading in the specified period.
Cost of electricity bill
The cost of electricity bill is calculated by multiplying the number of kWh that
were consumed by the cost of 1kWh.
For example, the electricity bill's cost for consumption of 9000 kWh per month with
cost of Rs.7.50/= for 1kWh is
9000 kWh x Rs.7.50/= Rs. 67,500/=.
Amps to kilowatts calculator
Amps (A) to kilowatts (kW) calculator.
AC single phase amps to kilowatts calculation
The power P in kilowatts (kW) is equal to the power factor PF times the current
I in amps (A), times the RMS voltage V in volts (V) divided by 1000:
P(kW) = PF × I(A) × V(V) / 1000
AC three phase amps to kilowatts calculation
The power P in kilowatts (kW) is equal to square root of 3 times the power factor
FP times the current I in amps (A), times the line to line RMS voltage VL-L in volts
(V) divided by 1000:
P(kW) = √3 × PF × I(A) × VL-L (V) / 1000
Amps to kVA calculator
Amps (A) to kilovolt-amps (kVA) calculator. Enter phase number, the current in amps,
the voltage in volts and press the Calculate button to get the apparent power in
kilovolt-amps:
Single phase amps to kVA calculation formula
The apparent power S in kilovolt-amps is equal to current I in amps, times the voltage
V in volts, divided by 1000:
S(kVA) = I(A) × V(V) / 1000
3 phase amps to kVA calculation formula
Calculation with line to line voltage
The apparent power S in kilovolt-amps is equal to current I in amps, times the line
to line voltage VL-L in volts, divided by 1000:
S(kVA) = √3 × I(A) × VL-L(V) / 1000
Calculation with line to neutral voltage
The apparent power S in kilovolt-amps is equal to current I in amps, times the line
to line voltage VL-N in volts, divided by 1000:
S(kVA) = 3 × I(A) × VL-N(V) / 1000
Amps to VA calculator
Amps (A) to volt-amps (VA) calculator and how to calculate. Enter phase number,
the current in amps, the voltage in volts and press the Calculate button, to get
the apparent power in volt-amps:
Single phase amps to VA calculation formula
The apparent power S in volt-amps is equal to current I in amps, times the voltage
V in volts:
S(VA) = I(A) × V(V)
3 phase amps to VA calculation formula
The apparent power S in kilovolt-amps is equal to square root if 3 current I in
amps, times the line to line voltage VL-L in volts:
S(VA) = √3 × I(A) × VL-L(V) = 3 × I(A) × VL-N(V)
Amps to volts calculator
Amps (A) to volts (V) calculator.
Select calculation type, enter amps and watts or ohms and press the Calculate button
to get volts:
Amps to volts calculation
The voltage V in volts (V) is equal to the power P in watts (W), divided by the
current I in amps (A):
V(V) = P(W) / I(A)
The voltage V in volts (V) is equal to the power P in watts (W), divided by the
current I in amps (A):
V(V) = I(A) × R(Ω)
Amps to watts calculator
Electric current in amps (A) to electric power in watts (W) calculator. Select current
type, enter current in amps, voltage in volts, power factor for AC circuit and press
the Calculate button (DC = Direct Current, AC = Alternating Current):
DC amps to watts calculation
The power P in watts (W) is equal to the current I in amps (A), times the voltage
V in volts (V): P(W) = I(A) × V(V)
AC single phase amps to watts calculation The power P in watts (W) is equal to the
power factor PF times the current I in amps (A), times the RMS voltage V in volts
(V): P(W) = PF × I(A) × V(V)
AC three phase amps to watts calculation The power P in watts (W) is equal to square
root of 3 times the power factor FP times the current I in amps (A), times the line
to line RMS voltage VL-L in volts (V): P(W) = √3 × PF × I(A) × VL-L(V)
Power factor calculator
Three Phase circuit calculation
KWh/KVAh = PF %
Single phase circuit calculation
PF = |cos φ| = 1000 × P(kW) / (V(V) × I(A))
Three phase circuit calculation
Calculation with line to line voltage
PF = |cos φ| = 1000 × P(kW) / (√3 × VL-L(V) × I(A))
Calculation with line to neutral voltage
PF = |cos φ| = 1000 × P(kW) / (3 × VL-N(V) × I(A))