USB Voltage Drop Calculator
Calculate the expected voltage drop along a USB cable given its length, current draw, and wire gauge.
Approximate calculation; check manufacturer specs for exact values.
Examples
- 2 A, 1 m, AWG 28 ⇒ 0.86 V
- 1 A, 2 m, AWG 24 ⇒ 0.34 V
FAQ
Why multiply by two for length?
Current travels to the device and back, doubling the resistance.
What if my gauge is different?
Use the closest AWG value; results are approximate.
Can voltage drop cause charging issues?
Yes, excessive drop can prevent devices from receiving sufficient power.
Additional Information
- Based on ohmic resistance per conductor.
- USB standards recommend keeping drop below 0.25 V for reliable operation.