Led Power Supply Calculator

LED Power Supply Calculator

5V 12V 24V 48V

Recommended Power Supply:

Total LED Strip Wattage: 0 W

Minimum PSU Capacity (with margin): 0 W

Required Amperage: 0 A

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How to Calculate the Correct LED Power Supply

Choosing the right power supply (driver) is critical for the longevity and safety of your LED lighting project. An undersized power supply will overheat and fail prematurely, while a correctly sized one ensures flicker-free operation.

The 80% Rule (Safety Margin)

In electrical engineering, it is standard practice to use the "80% Rule." This means you should only load your power supply to 80% of its maximum rated capacity. Conversely, this means you should calculate your total wattage and add a 20% safety margin to find the minimum power supply rating you need.

Step-by-Step Calculation

1. Find the Total Wattage: Multiply the length of your LED strip by the wattage consumption per unit of length (usually W/m or W/ft).
2. Apply the Safety Buffer: Multiply the total wattage by 1.2 (which adds a 20% overhead).
3. Determine Amperage: Divide the final wattage by the voltage of your system (12V or 24V) to find out how many Amps (A) the power supply must provide.

Practical Example

Suppose you have a 5-meter LED strip that consumes 14.4 Watts per meter at 12 Volts:

• Total Power Consumption: 5m × 14.4W = 72 Watts
• Adding Safety Margin: 72W × 1.2 = 86.4 Watts
• Required Amps: 86.4W / 12V = 7.2 Amps

In this scenario, you should look for a 12V DC power supply rated for at least 90W or 100W (standard sizes) or 7.5A to 10A.

function calculateLEDPower() { var length = parseFloat(document.getElementById('stripLength').value); var wattPerM = parseFloat(document.getElementById('wattPerMeter').value); var voltage = parseFloat(document.getElementById('voltage').value); var margin = parseFloat(document.getElementById('safetyMargin').value); if (isNaN(length) || isNaN(wattPerM) || isNaN(voltage) || isNaN(margin)) { alert("Please enter valid numeric values."); return; } // Calculation var totalWatts = length * wattPerM; var marginMultiplier = 1 + (margin / 100); var minPSU = totalWatts * marginMultiplier; var amps = minPSU / voltage; // Display Results document.getElementById('totalWatts').innerText = totalWatts.toFixed(2); document.getElementById('minPSU').innerText = minPSU.toFixed(2); document.getElementById('reqAmps').innerText = amps.toFixed(2); document.getElementById('led-results').style.display = 'block'; }