Measure the top
Record the object length and width at the widest points the tarp needs to cross.
Free Tarp Sizing Tool
Tarpaulin Size Calculator
Enter the object length, width and height, then specify the required side drop and edge overhang. The calculator returns a practical finished tarp size, total tarp area and a side-coverage check.
Calculation logic
Finished Length = Object Length + 2 × Drop + 2 × Overhang
Finished Width = Object Width + 2 × Drop + 2 × Overhang
Object height is used to check whether your selected drop reaches the bottom of the object.
Finished Width = Object Width + 2 × Drop + 2 × Overhang
Enter object dimensions
Use one unit consistently. You can change units at any time and the current values will be converted automatically.
m
Top length of the object.
m
Top width of the object.
m
Used to validate full side coverage.
m
Vertical tarp coverage down each side.
m
Added beyond the requested drop on every edge.
How to measure for a tarp cover
Measure the object itself first. Then decide how far the tarp should hang down the sides and how much extra material you want beyond that drop.
Choose the side drop
For full side coverage, set drop equal to the object height. Use a smaller drop when only partial side protection is required.
Add overhang
Add extra edge allowance for tying, tensioning, hems, irregular shapes or a looser fit.
Finished tarp formula
The calculator treats drop as the vertical distance the tarp hangs from the top edge. Overhang is additional material beyond that drop.
Finished size = top dimension + 2 × drop + 2 × overhang
Example tarp size calculation
For a 4.0 m × 2.0 m × 1.5 m object with a 1.5 m drop and 0.15 m overhang on each edge:
| Item | Calculation | Result |
|---|---|---|
| Finished tarp length | 4.00 + (2 × 1.50) + (2 × 0.15) | 7.30 m |
| Finished tarp width | 2.00 + (2 × 1.50) + (2 × 0.15) | 5.30 m |
| Finished tarp area | 7.30 × 5.30 | 38.69 m2 |
| Coverage check | Drop 1.50 m vs. object height 1.50 m | Full side coverage |
Related tarpaulin resources
Use these pages when the next step is material selection, specification or supplier quotation.
Tarpaulin size calculator FAQ
How do I calculate the finished tarp size for a rectangular object?
Add twice the required drop and twice the overhang to both the object length and width. This gives the flat finished size before any special shaping, seams or hardware requirements.
Should the drop equal the object height?
Use a drop equal to the object height when you want the tarp to reach the bottom of the object. A smaller drop gives partial side coverage, while a larger drop creates extra skirt material below the object base.
What is overhang in this calculator?
Overhang is extra material added beyond the selected side drop on every edge. Buyers often use it for tie-down clearance, tensioning, hems or a looser fit.
Does the calculator include seam, hem or shrinkage allowance?
No. The result is a geometric finished-size recommendation. Manufacturing tolerances, welded hems, reinforced edges, webbing, grommets and material shrinkage should be confirmed with the tarp manufacturer before production.
Can I use inches or feet?
Yes. Choose meters, centimeters, millimeters, feet or inches. When you change units, the entered dimensions are converted automatically.
Need a custom finished tarp size?
Send DERFLEX the object dimensions, installation method, material requirement, edge reinforcement and hardware details for a production-ready recommendation.