All Tools

Free calculators and reference tools for USB, cables, power, charging, and electronics.

Calculate power (W), current (A), voltage (V) and resistance (Ω) with ease.

Estimate charging time based on battery capacity, charger power and efficiency.

Compare USB standards and their real-world speed, bandwidth and features.

Calculate voltage, current or resistance using Ohm’s Law formulas.

Decode 3, 4, 5 and 6 band resistor values and tolerances.

Check recommended USB cable lengths for data and charging reliability.