How it works
V=I×R; I=V/R; R=V/I. Power=V×I for the calculated operating point.
Input definitions
- Solve for
- Choose Voltage / Current / Resistance.
- Voltage V (ignored when solving voltage)
- Enter the value in the labeled unit.
- Current A (ignored when solving current)
- Enter the value in the labeled unit.
- Resistance Ω (ignored when solving resistance)
- Enter the value in the labeled unit.
A worked example
- Solve for
- Voltage
- Voltage V (ignored when solving voltage)
- 20
- Current A (ignored when solving current)
- 2
- Resistance Ω (ignored when solving resistance)
- 10
Assumptions & limits
Ideal DC ohmic resistance; non-negative inputs. Not an electrical installation, component rating or personal-safety assessment.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Does this replace a circuit or electrical safety assessment?
No. The result uses the idealized model shown. Component tolerance, temperature, fault conditions and installation requirements need separate evaluation.
How does the Ohm’s law and electrical power tool work?
V=I×R; I=V/R; R=V/I. Power=V×I for the calculated operating point.
What are the assumptions and limits of Ohm’s law and electrical power?
Ideal DC ohmic resistance; non-negative inputs. Not an electrical installation, component rating or personal-safety assessment.