Calculators
Electronics calculators
Each one updates as you type and runs in your browser. The formulas are the ones the lessons are checked against, and every page links down to the lessons that explain the answer.
Resistor colour code calculator
Bands to ohms and ohms to bands, with the tolerance range and the nearest standard value.
Background: The resistor colour code
LED resistor calculator
One LED or a string: exact and standard resistor, real current, resistor wattage.
Background: LED circuits
Voltage divider calculator
Loaded and unloaded output, tolerance spread, and the best standard pair for a target.
Background: The voltage divider
Capacitor code calculator
Printed code to pF, nF and µF with tolerance and voltage, and a value back to its code.
Background: Capacitor markings
SMD resistor code calculator
Three-digit, four-digit, R and EIA-96 codes both ways, with checks on what you typed.
Background: SMD resistor codes
LM317 calculator
R1 and R2 both ways, headroom, dissipation, heatsink, and the one-resistor current source.
Background: Linear regulators
Inverter battery backup calculator
Backup hours for a home inverter, or the battery size a target time needs.
Background: Battery types
Looking for the AI tools, such as Datasheet Guru? They live under tools. Author of the calculators: Bulan Sarkar. Found a wrong number? Tell us.