Load Tarpaulin Size: Cover Dimensions over a Load, Eyelets, Area & Mass

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 7 inputs are read from the form on every keystroke: Load Length, Load Width, Load Height above the Deck, Extra to Tie Down, Each Edge, Hem Allowance, Each Edge, Eyelet Spacing and Fabric Weight.
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Finished Sheet Area together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Finished Width, Finished Length, Cut Width with Hems, Cut Length with Hems, Fabric Cut, Eyelets round the Edge, Sheet Mass and Share of the Sheet on Top of the Load — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Four-fifths of the sheet hangs down the sides. The top is the small part.

How to use it

1. Work through the input groups in order — Load and Sheet. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Finished Sheet Area in the dark results panel — that is the headline figure, expressed in m².
4. Check the supporting rows underneath (Finished Width, Finished Length, Cut Width with Hems, Cut Length with Hems, Fabric Cut, Eyelets round the Edge, Sheet Mass and Share of the Sheet on Top of the Load) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Finished Sheet Area before a trial is booked, so machine time and material in Leather, Coated Fabrics & Tarpaulins are committed against a calculated figure rather than an estimate.
• Costing and quotation — Finished Sheet Area is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Load Length) shows how much of the gap in Finished Sheet Area each variable explains.
• Teaching and study — the accepted ranges bracket normal Leather, Coated Fabrics & Tarpaulins practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• The sheet covers the top of the load, comes down all four sides to the deck and goes on by the tie-down allowance; for a stockpile on the ground, enter the height of the pile and the length to weight down. Load dimensions, hems and eyelet spacing are yours. Eyelets are counted along each edge at the spacing given, with one at every corner. Mass is the cut fabric at its weight per square metre; eyelets, ropes and any welded seams joining fabric widths are extra. A sheet wider than the fabric is made from joined widths, which this does not count. **This is a size take-off, not a load-securing check: the ropes and straps hold the load, not the sheet.**
• Every input is bounded to the range normal practice occupies (Load Length 0.5 to 30 m, Load Width 0.3 to 10 m and Load Height above the Deck 0 to 5 m, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• EN 12195-1, Load restraining on road vehicles, safety: calculation of securing forces, for the straps and lashings that hold the load (the sheet does not).
• The fabric data sheet: weight per square metre, tensile and tear strength, and coating.

Questions people ask