Pricing Model: Weight per Length

The Weight per Length pricing model is for materials you buy as a continuous quantity measured by weight (grams, kilograms) or by length (metres, centimetres). You enter the total quantity and total price; CrafterBy calculates a cost per unit of measure, which you then apply when specifying how much you use per product.

When to use it

Use Weight per Length when:

• You buy the material by a length measurement (metres of ribbon, wire, cord) or by weight (chain by the gram, beads by the 100g)
• You use a measured portion per product

Good examples:

• Cotton thread — 500 m spool for €8.00
• Leather cord — 10 m roll for €12.50
• Sterling silver chain — bought by the gram
• Elastic — 25 m roll for €7.00
• Copper wire — 100 m spool for €15.00

Setting up a Weight/Length material

1. Follow the steps in Adding a Material.
2. Select Weight per Length as the pricing model.
3. Choose the Unit of Measure (metres, centimetres, grams, kilograms).
4. Enter the Total Quantity purchased in that unit.
5. Enter the Purchase Price for that quantity.
6. CrafterBy calculates: Cost per unit = Purchase Price / Total Quantity.

Adding it to a product

When you add a Weight/Length material to a product, enter the quantity used per product in the same unit you set up. CrafterBy multiplies the quantity by the cost per unit.

Worked example

You have a 500 m spool of cotton thread that cost €8.00.

• Unit: metres
• Total quantity: 500 m
• Purchase price: €8.00
• Cost per metre: €8.00 / 500 = €0.016/m

A friendship bracelet uses 35 cm (0.35 m) of thread.

• Material cost: 0.35 m × €0.016 = €0.0056

A macrame wall hanging uses 45 m of the same thread.

• Material cost: 45 m × €0.016 = €0.72

Tip: units must be consistent

If you set up the material in metres, always enter product usage in metres. If you find yourself doing mental conversion at the product level, it is easier to set the material up in a smaller unit (e.g., centimetres) so that product quantities are whole numbers.