This comes up often when people try to power LEDs, [sensors](https://www.ampheo.com/c/sensors), or even motors directly from [Arduino](https://www.ampheo.com/c/development-board-arduino) pins.

**General Limits (Typical [ATmega328P](https://www.ampheo.com/search/ATmega328P), e.g. [Arduino Uno](https://www.ampheo.com/product/a000046-25542493)/Nano)**

**Per I/O pin:**

* Maximum 40 mA (absolute max) per pin.
* Recommended safe current: ≤20 mA to avoid stressing the [microcontroller](https://www.ampheo.com/c/microcontrollers).
* Beyond 40 mA, permanent damage is possible.

**Total per port (group of 8 pins):**

About 100 mA max per port (e.g., PORTB, PORTC, PORTD on ATmega328P).

**Total for the whole chip (Vcc & GND pins combined):**

200 mA max absolute across all I/O and supply pins.

**Important Notes**

* LEDs: A single LED with a current-limiting resistor (e.g., 5–15 mA) is safe. Don’t try to power multiple LEDs in parallel directly from one pin.
* Motors, relays, servos: Never power them directly from a GPIO pin — use a [transistor](https://www.onzuu.com/category/transistors), [MOSFET](https://www.onzuu.com/category/fets-mosfets), or driver IC.
* Sensors/modules: Many digital ICs draw only a few mA, so they’re safe to power from a pin, but always check the datasheet.

**Quick reference table**

**Summary:**
An [Arduino](https://www.ampheoelec.de/c/development-board-arduino) digital I/O pin can source or sink up to 40 mA max, but for reliability keep it at 20 mA or less. For higher-current loads (LED strips, motors, [relays](https://www.onzuu.com/category/relays)), always use a driver transistor, MOSFET, or dedicated IC.