Electrical & digital
Ohm’s law & DC power Calculator
Find voltage, current and power for a purely resistive circuit. This free ohm’s law & dc power calculator shows the calculation and its assumptions so you can compare your own figures.
Calculated on your device
Your results
Current Amps2 A
Find voltage, current and power for a purely resistive circuit.
Power Watts24 W
Calculated outcomes
- Voltage Volts
- 12 V
Assumptions and estimates
- DC or purely resistive circuit: V=IR and P=VI. Component tolerances, temperature, AC impedance and electrical safety limits are not modelled. Use power ratings and installation standards separately.
- Method: DC/resistive V=IR and P=VI; resistance must be greater than zero.
- Editable inputs are planning assumptions; check the method and result notes for scope.
Useful next steps
- Use Compare options to test an alternative side by side.
- Copy, print or download a record of this calculation when you need one.
Reports open your email app addressed to s@s1.ie with the public page address only. Your inputs are never added.
How the ohm’s law & dc power calculation works
DC/resistive V=IR and P=VI; resistance must be greater than zero.
Editable inputs are planning assumptions; check the method and result notes for scope.
Using this calculator
- Enter your own figures in the labelled inputs. Keep the currencies, units and time periods consistent.
- Choose any applicable rate profile, pattern or assumption shown for this tool. Open additional inputs when relevant.
- Review current amps and power watts, then read the stated assumptions and eligibility conditions before using the result.
Worked example
This is a static example using illustrative inputs, not facts about you or today’s date. The displayed eligibility selections and assumptions apply only to this example.
See example inputs
- Known electrical value
- Voltage (V)
- Known voltage (V) or current (A)
- 12
- Resistance (Ω)
- 6
- Current Amps
- 2 A
- Power Watts
- 24 W