Free Electronics Calculators for Engineers
A set of practical electronics calculators for maintenance engineers, industrial technicians and plant managers. Whether you are working on a PCB, a drive, a control panel or a power supply, these tools help you identify component values and verify circuit calculations quickly — no sign-up required.
What Calculators Are Available?
Frequently Asked Questions
Each coloured band on a resistor represents a number or multiplier. The first two or three bands are the significant digits, the next band is the multiplier, and the last band indicates tolerance. Use the resistor colour code calculator above to decode any 4, 5 or 6 band resistor instantly.
Ohm's Law states that Voltage (V) equals Current (I) multiplied by Resistance (R). It also connects to Power (P = V × I). If you know any two of these four values, the other two can be calculated automatically. The Ohm's Law calculator above does this instantly.
A voltage divider uses two resistors in series to produce a lower output voltage from a higher input. It is widely used in industrial control circuits for reference voltages, sensor signal conditioning and analogue input scaling on PLCs and control boards.
Yes. All calculators on this page are completely free. No account, no registration and no download required. They are provided by Northern Power Electronics as a resource for engineers working on industrial electronic systems.
Yes. Our engineers use professional diagnostic equipment including ABI BoardMaster in-circuit testing to identify and replace failed components on industrial PCBs — including boards with no schematics. Send us your equipment for assessment.
Resistor Colour Code Calculator — Decode 4, 5 and 6 band axial resistors. Select each band colour to display the resistance value, tolerance and temperature coefficient.
Ohm's Law Calculator — Enter any two of Voltage, Current, Resistance or Power and the remaining values are calculated automatically.
Voltage Divider Calculator — Calculate the output voltage from a two-resistor voltage divider circuit. Commonly used in sensor circuits and industrial control systems.
Need Industrial Electronics Repaired?
Northern Power Electronics repairs industrial electronics at component level — PCBs, AC and DC drives, servo amplifiers, power supplies, HMIs and control panels.
Based in Newcastle upon Tyne, we serve manufacturing plants, offshore platforms and industrial facilities across the UK.
Select each band colour to identify the resistance value
Enter any two values — the others calculate automatically
Calculate output voltage from Vin, R1 and R2