What width webbing should I use?

25mm is the most common for bag straps and dog leads. 38mm suits larger bags and backpacks. 50mm for belts and heavy-duty straps. Match the webbing width to your hardware (buckles, sliders, D-rings).

How much extra do I need for hardware?

Allow 5-10cm per end for looping through hardware (buckles, D-rings, sliders). An adjustable strap needs extra length: the adjustment range plus hardware allowances on both ends.

What type of webbing should I use?

Polypropylene: lightweight, does not absorb water, good for outdoor use. Cotton: soft, comfortable for handles, takes dye well. Nylon: strong, abrasion resistant, good for heavy loads. Polyester: UV resistant, colourfast.

How do I seal the ends of webbing?

Synthetic webbing (polypropylene, nylon): seal cut ends with a flame to prevent fraying. Cotton webbing: fold ends under or cover with a fabric tab. Always seal before sewing.

SewCalcs

Webbing Calculator — Bag Straps & Belts

Calculate webbing length for bag straps, belts and hardware.

Strap Type

Finished Strap Length

Number of Straps

Hardware Allowance

Extra for buckles, D-rings etc.

Webbing Price (optional)

How We Calculate This

Total webbing is the finished strap length plus allowances for wrapping through hardware at each end, multiplied by the number of straps.

The formula

Per strap = Finished length + Hardware allowance

Total webbing = Per strap × Number of straps

Frequently Asked Questions

Related Calculators

Button Spacing Calculator

Calculate even button spacing and placement for garments.

Elastic Calculator

Calculate elastic length for waistbands, cuffs and casings.

Ribbon Calculator

Work out ribbon length needed for trims, bows and decoration.

Hook and Eye Calculator

Calculate hook and eye spacing and quantities for closures.

Snap Spacing Calculator

Calculate even snap placement and quantities.

Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.