Stretch Film Weight Calculator

Enter the roll length (ft), the roll width (in), and the film gauge into the Stretch Film Weight Calculator. The calculator will evaluate the Stretch Film Weight. 

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Stretch Film Weight Guide

The stretch film weight calculator estimates the weight of a roll of film from its length, width, and gauge. It can also be used in reverse when you know the target roll weight and need to solve for a missing dimension or thickness. This is useful for purchasing, freight planning, inventory control, and verifying that a film specification matches the expected roll weight.

Stretch Film Weight Formula

SFW = \frac{L \times W \times G}{250000}

In this relationship, weight changes directly with every input. If length, width, or gauge increases, film weight increases in the same proportion.

Rearranged Forms

If one value is unknown, the same formula can be rearranged to solve for it:

L = \frac{250000 \times SFW}{W \times G}

W = \frac{250000 \times SFW}{L \times G}

G = \frac{250000 \times SFW}{L \times W}

What Each Input Means

• Roll Length: the total length of film on the roll.
• Roll Width: the width of the film web, measured across the roll.
• Film Gauge: the thickness specification of the film.
• Stretch Film Weight: the calculated film-only weight. If you need total shipped roll weight, add the core weight separately.

How the Inputs Affect the Result

• If the roll length doubles, the film weight doubles.
• If the roll width doubles, the film weight doubles.
• If the gauge doubles, the film weight doubles.
• A 10% increase in any one input causes a 10% increase in weight.
• If two inputs both increase, their effects multiply together.

SFW_2 = SFW_1 \times \frac{L_2}{L_1} \times \frac{W_2}{W_1} \times \frac{G_2}{G_1}

This makes the formula especially helpful when comparing alternate film specifications. For example, reducing gauge lowers weight directly, while increasing width or length raises material usage at the same rate.

Unit Notes

If you are entering metric values, use the calculator’s unit selectors so the inputs are converted correctly. A common source of error is mixing gauge and mil values.

1\ \text{mil} = 100\ \text{gauge}

1\ \text{mil} = 0.0254\ \text{mm}

That means a film listed as 1.5 mil is the same as 150 gauge. If the wrong thickness unit is entered, the calculated weight can be off by a large amount.

Examples

Example 1: Find the film weight

Suppose a roll has a length of 120 ft, a width of 30 in, and a gauge of 150.

SFW = \frac{120 \times 30 \times 150}{250000} = 2.16\ \text{lb}

Example 2: Find the required gauge

If a roll must weigh 3 lb, and the roll length is 200 ft with a width of 20 in, solve for gauge:

G = \frac{250000 \times 3}{200 \times 20} = 187.5

So the required film thickness is about 188 gauge.

Common Input Mistakes

• Entering roll diameter instead of total roll length.
• Using centimeters while inches is selected, or meters while feet is selected.
• Entering mil as if it were gauge.
• Assuming the result includes the weight of the core.
• Rounding the gauge too early before finishing the calculation.

When This Calculator Is Most Useful

• Comparing two film options before ordering.
• Estimating inbound or outbound shipment weights.
• Checking whether a supplier’s roll specification is reasonable.
• Planning storage loads and inventory counts.
• Estimating material use for packaging operations.

Quick Process

1. Enter any three known values.
2. Confirm that the selected units match the numbers being entered.
3. Calculate the missing value.
4. Review whether the result represents film-only weight or total roll weight with core.

Because the formula is linear, this calculator is also effective for fast what-if checks. Small changes in length, width, or gauge immediately show how material weight will change, making it easier to balance load size, film strength, and shipping efficiency.