Loading Meters (LDM)

Loading meters (LDM) is a standard calculation in cargo transportation that determines how much space shipments occupy lengthwise in a truck.

Basic Formula

Formula: (Length × Width) / 2.4 = LDM

The divisor 2.4 represents the standard internal width of a truck in meters.

use function Cline\Volume\volume;

// Single Euro pallet (1.2m × 0.8m)
$vol = volume([120, 80, 100]); // dimensions in centimeters
$ldm = $vol->loadingMeters();
$ldm->value(); // 0.4 LDM (1.2 × 0.8 ÷ 2.4 = 0.4)

// Formatted output
$ldm->format(2); // "0.40"

Quantity Parameter

When shipping multiple identical items:

Formula: Quantity × (Length × Width) / 2.4 = Total LDM

// 5 Euro pallets via Volume API
$vol = volume([120, 80, 100]);
$ldm = $vol->loadingMeters(quantity: 5);
$ldm->value(); // 2.0 LDM (5 × 0.4 = 2.0)

// Direct instantiation
$ldm = LoadingMeter::fromCentimeters(120, 80, quantity: 5);
$ldm->value(); // 2.0 LDM

Stacking Factor

For stackable goods, divide by the stacking factor:

Formula: (Length × Width) / 2.4 / Stacking Factor = LDM

// Euro pallet stackable 2 high
$ldm = LoadingMeter::fromCentimeters(120, 80, stackingFactor: 2.0);
$ldm->value(); // 0.2 LDM (0.4 ÷ 2 = 0.2)

// Via Volume API
$vol = volume([120, 80, 100]);
$ldm = $vol->loadingMeters(stackingFactor: 2.0);
$ldm->value(); // 0.2 LDM

Combined: Quantity + Stacking

Formula: Quantity × (Length × Width) / 2.4 / Stacking Factor = Total LDM

// 10 Euro pallets, stackable 2 high
$ldm = LoadingMeter::fromCentimeters(120, 80, quantity: 10, stackingFactor: 2.0);
$ldm->value(); // 2.0 LDM ((10 × 0.4) ÷ 2 = 2.0)

Custom Truck Width

For non-standard trucks, specify the actual truck width:

// Using a 3-meter wide truck
$ldm = LoadingMeter::fromCentimeters(120, 80, truckWidth: 3.0);
$ldm->value(); // 0.32 LDM ((1.2 × 0.8) ÷ 3.0 = 0.32)

Complete Example

use Cline\Volume\ValueObjects\LoadingMeter;

$ldm = LoadingMeter::fromCentimeters(
    lengthInCm: 120,
    widthInCm: 80,
    quantity: 6,           // 6 pallets
    stackingFactor: 3.0,   // stackable 3 high
    truckWidth: 2.5,       // 2.5m wide truck
);

// (6 × (1.2 × 0.8)) / 2.5 / 3.0 = 0.768 LDM
$ldm->value(); // 0.768

// Access parameters used in calculation
$ldm->quantity;        // 6
$ldm->stackingFactor;  // 3.0
$ldm->truckWidth;      // 2.5
$ldm->length;          // 120.0 (cm)
$ldm->width;           // 80.0 (cm)

API Reference

LoadingMeter::fromCentimeters()

public static function fromCentimeters(
    float $lengthInCm,
    float $widthInCm,
    int $quantity = 1,
    float $stackingFactor = 1.0,
    float $truckWidth = 2.4,
): LoadingMeter

LoadingMeter::fromMeters()

public static function fromMeters(
    float $length,
    float $width,
    int $quantity = 1,
    float $stackingFactor = 1.0,
    float $truckWidth = 2.4,
): LoadingMeter

Instance Methods

Method	Return	Description
value()	float	Raw loading meter value
format(int $decimals = 2)	string	Formatted with number_format
__toString()	string	String representation