Calculate unknown circuit values with practical formulas. Compare series, parallel, and power behavior in seconds. Review clean outputs, graphs, and exports for better decisions.
| Scenario | Voltage | Current | Resistance | Power |
|---|---|---|---|---|
| Single resistor load | 12 V | 2 A | 6 Ω | 24 W |
| Small heater | 24 V | 3 A | 8 Ω | 72 W |
| Series string | 18 V | 0.3 A | 60 Ω | 5.4 W |
| Parallel branch bank | 9 V | 0.45 A | 20 Ω | 4.05 W |
Voltage equals current multiplied by resistance.
V = I × R
Current equals voltage divided by resistance.
I = V / R
Resistance equals voltage divided by current.
R = V / I
P = V × I
P = I² × R
P = V² / R
Total resistance is the sum of all resistors.
Rₜ = R₁ + R₂ + R₃ + ...
Current stays the same through each component.
Voltage drop across each resistor equals current multiplied by branch resistance.
The reciprocal of total resistance equals the sum of branch reciprocals.
1 / Rₜ = 1 / R₁ + 1 / R₂ + 1 / R₃ + ...
Voltage stays the same across every branch.
Branch current equals branch voltage divided by branch resistance.
An Ohms circuit calculator helps you solve electrical values fast. It reduces manual work. It also lowers common wiring and troubleshooting mistakes. You can use it for simple loads, series circuits, parallel branches, and power checks. That makes planning easier.
This tool solves voltage, current, resistance, and power. It also evaluates full series and parallel resistor networks. That makes it useful for students, technicians, hobby builders, and maintenance teams. You can test one unknown value or review a complete branch breakdown.
Single component calculations are direct. Series circuits behave differently. The same current flows through every resistor. Parallel circuits also behave differently. Every branch sees the same voltage. These rules change total resistance, current draw, voltage drop, and power use. A dedicated mode prevents wrong assumptions.
The result section shows the core values first. That keeps the most important numbers easy to read. The detailed tables then show branch level behavior. This helps with resistor sizing, power checks, and load balancing. The graph adds a quick visual comparison. You can spot large voltage drops or heavy branch currents faster.
CSV export is useful for reports, job files, audits, and spreadsheets. PDF export is useful for printing, sharing, and review meetings. Both options help you document how each electrical result was produced. That is valuable during installation planning and later troubleshooting.
Use correct units. Enter volts for voltage. Enter amps for current. Enter ohms for resistance. Enter only positive resistor values. For resistor lists, separate each value clearly. Double check supply voltage before calculating. Good input gives dependable output. That is the fastest path to a reliable circuit decision.
It solves voltage, current, resistance, and power. It also calculates total values for series and parallel resistor circuits, including branch details and useful electrical summaries.
Yes. In the Ohms law and power modes, enter at least two known values. The calculator can solve the missing electrical value from the information provided.
Series circuits keep the same current through each resistor. Parallel circuits keep the same voltage across each branch. That changes total resistance and power behavior.
Each new branch creates another path for current. More current paths reduce the equivalent resistance seen by the source. That is why parallel networks draw more current.
Yes. Decimal values work in every mode. That is helpful for precision resistors, measured loads, and practical electrical testing where values are not whole numbers.
Power shows how much electrical energy a load consumes. It helps with resistor wattage selection, thermal checks, supply sizing, and safe component planning.
Use volts for voltage, amps for current, ohms for resistance, and watts for power. Keeping unit input consistent helps prevent incorrect electrical results.
Use it during circuit design, maintenance checks, resistor selection, power verification, classroom practice, and troubleshooting. It is useful before wiring and after measurements.