24V vs 48V Linear Lighting: Run Length & Voltage Drop

Short answer

For the same wattage, a 48V system draws half the current of a 24V system. Voltage drop in the wiring halves in volts, and as a percentage of the supply voltage it falls to a quarter. So 48V products can run longer from one feed, with fewer drivers and lighter wire. Choose 24V when you need short cut increments (tight millwork), the product you need only comes in 24V, or the location’s rules make a lower voltage preferable.

Key takeaways

Current: I = P ÷ V. Double the voltage, half the current.

Voltage drop: VD = 2 × L × I × R. Half the current, half the drop.

48V typically allows longer runs per feed; check the product’s published maximum.

24V usually offers shorter cut points and a wider product choice.

The two formulas

current I (A) = power P (W) ÷ voltage V (V)

voltage drop VD (V) = 2 × one-way length L (ft) × I (A) × R (Ω/ft)

The factor 2 is there because current flows out and back. R is the conductor resistance per foot (per 1000 ft ÷ 1000).

Worked example: same load, two voltages

A 96 W load fed from a remote driver over 30 ft of 16 AWG copper (4.016 Ω per 1000 ft).

	24V	48V
Current (96 W ÷ V)	4.0 A	2.0 A
Voltage drop (2 × 30 × I × 0.004016)	0.96 V	0.48 V
Drop as % of supply	4.0%	1.0%

The same wiring that is marginal at 24V is comfortable at 48V. At 24V you would either move the driver closer, use heavier wire (14 AWG: 2.525 Ω/1000 ft gives 0.61 V, 2.5%) or split the load.

Voltage drop also happens inside the LED product along its length, which is why manufacturers publish a maximum run per feed. That limit is typically longer for 48V versions of the same product.

When each makes sense

Choose 48V when	Choose 24V when
Long coves, perimeters and continuous runs	Short runs in millwork, shelves, handrails
Drivers must be far from the run	You need short cut increments
You want fewer feeds and drivers	The exact product needed only exists in 24V
Dry locations where 48V is permitted	Wet locations where a lower voltage is required

Checklist

Get the product’s W/ft, voltage and maximum run per feed.
Size drivers: see how to size an LED driver.
Measure the one-way wire length from each driver to its run.
Calculate voltage drop; change gauge, driver location or voltage until it is within the target.

Frequently asked questions

Is 48V still Class 2?

Class 2 limits depend on voltage, power and location, and they are lower for wet locations. Check the driver’s Class 2 marking and the code requirements for the location before using 48V outdoors or in wet areas.

How much voltage drop is acceptable?

Follow the product manufacturer’s limit. A common design target is to keep drop on the low-voltage side to a few percent (about 3–5%) so the far end of the run is not visibly dimmer.

Can I mix 24V and 48V products on one driver?

No. Each driver output has one voltage; use separate drivers.

24V vs 48V linear lighting