Low-Voltage DC Drop

DC voltage drop and percent at 12 / 24 / 48 V with application-tolerance flags.

Run the calculator

Formula and source

VD = 2 × I × R × L for 12 / 24 / 48 V DC systems with copper resistance per NEC Chapter 9 Table 8.

NEC 2023 (NFPA 70). Chapter 9 Table 8 (used as a copper-resistance reference, not as a low-voltage code).

Audience

This tile is built for electricians and the adjacent professions in the Electrical group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.

Related tools

Posture

Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.