LED Strip Power Calculator - Online PSU & Controller Sizing

LED strips can draw their maximum rated power under full brightness white. Running a PSU at 100% load 24/7 causes excessive heat, reduces efficiency, and dramatically shortens its lifespan. A 20% margin ensures the PSU runs cool and handles momentary surges. For critical installations or enclosed spaces, consider a 30% margin.

5V: Best for short runs (<3m) and addressable LEDs like WS2812B. Higher current means more voltage drop over distance.
12V: The sweet spot for most projects. Good for runs up to 5-6m without injection. WS2815 uses 12V with built-in backup data.
24V: Ideal for long runs (8m+) and architectural lighting. Less voltage drop, more efficient. Great for single-color or analog strips.

Voltage drop occurs when current travels through the thin copper traces of an LED strip, causing the far end to receive less voltage. This results in dimmer LEDs, color shifts (especially with white), and flickering. Prevention: use higher voltage strips (12V/24V), inject power at multiple points along the strip, use thicker gauge wire for power runs, and keep strip lengths within recommended limits.

Power injection means connecting the PSU directly to multiple points along a long LED strip (not just the beginning). For 5V strips, inject every 2-3 meters. For 12V strips, inject every 4-5 meters. For 24V strips, inject every 8-10 meters. Always connect injection wires to the same PSU — never use separate PSUs on the same strip unless you isolate the positive lines.

Addressable (Digital): Each LED has its own IC chip (WS2812B, SK6812, WS2815), allowing individual control of every LED's color and brightness. Requires a data controller. Perfect for animations and effects.
Analog: The entire strip changes color at once. Uses MOSFET/PWM controllers that vary voltage per color channel. Simpler and cheaper, but no per-LED control. Good for uniform ambient lighting.

For addressable strips, match the controller to your total pixel count and desired features: SP107E (up to 600 pixels, Bluetooth), SP108E (up to 800 pixels), SP602E (up to 1200 pixels, WiFi). For large projects, consider WLED on ESP32 with a Dig-Uno or Dig-Quad. For analog strips, check the controller's per-channel current rating — it must exceed your strip's per-channel draw.

Yes — wire strips in parallel to the PSU, not in series. Connecting strips end-to-end in series increases voltage drop. Instead, run separate power wires from the PSU to each strip or injection point. The PSU's total wattage must cover the sum of all strips plus the 20% margin. Use a fused distribution board for safety on larger installs.

Calculate: Total Watts ÷ 1000 × Hours per day × Electricity rate ($/kWh) × 30 days. Example: 90W strip running 6 hours/day at $0.15/kWh = 90/1000 × 6 × 0.15 × 30 = $2.43/month. LED strips are very cost-effective compared to traditional lighting. Using brightness control or effects can reduce actual consumption significantly below the maximum rating.