Why does fibre content matter when blending yarns?

Fibre content affects how the finished fabric behaves: its warmth, drape, stretch, washability, and how it responds to blocking. When you hold two yarns together, the resulting fabric has properties of both fibres in proportion to their percentages. Knowing the blend helps you predict how the fabric will perform.

How do I find fibre content percentages?

Check the ball band (label) on your yarn. It will list fibre content as percentages, e.g. "75% Merino Wool, 25% Nylon". If the ball band is missing, you can do a burn test: wool smells like burning hair, cotton smells like burning paper, and synthetic fibres melt. However, burn tests only identify the dominant fibre.

Can I combine any two yarns together?

You can combine any yarns, but consider the care requirements. If one yarn is dry-clean only (e.g. mohair) and the other is machine washable (e.g. superwash wool), the finished item must be cared for according to the most delicate yarn. Also consider that the combined weight will be heavier than either yarn alone, affecting gauge and drape.

KnitCalcs

Fibre Content Calculator — Blend Percentages for Combined Yarns

Calculate the blended fibre percentages when holding two yarns together or combining different fibre blends.

Yarn 1

Weight used

Fibre 1 %

Fibre 2 % (optional)

Yarn 2

Weight used

Fibre 1 %

Fibre 2 % (optional)

How We Calculate This

This calculator works out the overall fibre content when you combine two yarns with different compositions. It calculates the weight of each fibre type and expresses it as a percentage of the total combined weight.

The formula

Grams of fibre = Yarn weight x (Fibre percentage / 100)

Blended percentage = Grams of fibre / Total combined weight x 100

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard yarn weights and gauge. Results may vary with individual tension, yarn brand, and needle size.