LM317 Calculator

Calculate V, I, or R based on Ohm's Law.

Find a resistor's value by its color bands.

Find the right resistor for your LED.

Estimate how long a battery will last.

Determine battery capacity based on load and runtime.

Convert units of voltage.

Convert units of electrical current.

Convert units of frequency.

Convert units of electrical charge.

Calculate power dissipation in resistor circuits.

Convert RF power between watts and decibels.

Calculate thermal resistance for heat transfer.

Calculate values for Zener diode circuits.

Calculate values for a DC-DC buck converter.

Estimate the wattage needed for your PC build.

Estimate your electrical load and consumption.

Calculate power, voltage, current, or resistance.