Electronics CalculatorsWhat is here
Six calculators for the sums that come up again and again when you build small circuits, five guides with worked examples and a chart of wire sizes.
| You want to... | Use |
|---|---|
| Find voltage, current, resistance or power | Ohm's law calculator |
| Read or choose resistor colours | Resistor colour code calculator |
| Protect an LED | LED resistor calculator |
| Combine resistors | Series and parallel calculator |
| Reduce a voltage for a signal | Voltage divider calculator |
| Size an RC filter or delay | RC time constant calculator |
Safety
The calculators are for low-voltage electronics. Mains voltage (230 V in India) can kill. Work on mains wiring only if you are qualified, and always check the power rating of parts.
Are the results accurate?
The sums are exact. Real parts have tolerances, so build in a margin.
Do you give circuit diagrams?
Not yet. The guides use numbers and tables.
This is an independent guide. It is not connected with any standards body or company named here. The formulas are the usual textbook ones; the colour code, E-series and AWG values are those printed in common references, because the standards IEC 60062, IEC 60063 and ASTM B258 are paid documents that we did not read. Tables and examples were calculated with Python on 14 November 2026. Check data sheets and local safety rules before you build.