calc / circuit tools
Circuit Design Tools
Pick a calculation, change the values, and watch the circuit diagram explain what the numbers mean.
Ohm's Law
Inputs update instantly; diagrams show the electrical idea behind the result.
Enter any two of voltage, current, and resistance.
- Voltage
- 12 V
- Current
- 2 A
- Resistance
- 6 Ω
Educational bench
Learn the circuit while you calculate
This is twelve small, single-purpose calculators grouped into one tool, each solving a specific circuit-design problem: Ohm's Law and power dissipation (solve for whichever of voltage, current, resistance, or power you don't already know), voltage dividers, RC and RLC time-constant/resonance calculations, series and parallel resistor equivalence, Delta-Wye (Y-Δ) three-phase network transforms, a current-limiting resistor sizer for LEDs, an IPC-2221-style PCB trace width estimator, transformer turns-ratio/voltage conversion, and power factor from either real/apparent power or a phase angle.
Each tool is independent — pick it from the row of buttons above the form, and only the fields that specific calculation needs are shown. Ohm's Law and Power Dissipation both accept any two of voltage/current/resistance and solve for the rest, the same way a physical Ohm's Law wheel works, rather than forcing you to rearrange the formula yourself.
- 1Pick a tool from the row of buttons — each is a self-contained calculator with its own fields.
- 2Enter the known values; the result updates as you type.
- 3For Ohm's Law, Power Dissipation, and Delta-Wye, only the fields needed for that direction are required — leave the value you want solved for blank where applicable.
Frequently asked questions
Do I need to know which formula to use for Ohm's Law?
No — enter any two of voltage, current, and resistance and the calculator solves for the third automatically, using whichever of V=IR, I=V/R, or R=V/I applies.
How accurate is the PCB trace width calculator?
It uses the standard IPC-2221 approximation formula for external and internal copper layers, which is a well-established first-pass estimate. For high-current traces or unusual board constructions, check your PCB manufacturer's own capability tables as well.
What is a Delta-Wye (Y-Δ) transform used for?
It converts a three-resistor network from a delta (triangle, resistors between each pair of terminals) configuration to an equivalent wye (star, resistors from each terminal to a common center) configuration, or back — useful for simplifying three-phase circuits or resistor networks that aren't simple series/parallel combinations.
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