KnitCalcs
Colour Block Calculator — Calculate yarn for colour block sections.
Calculate yarn for colour block sections.
How We Calculate This
This calculator divides your total yarn requirement by colour percentage to estimate how much of each colour you need.
The formula
Colour yarn = Total yarn x Colour percentage / 100
With extra = Colour yarn x (1 + Extra %) + tail waste
Each colour change leaves two tails to weave in — one in the colour that ends and one in the colour that begins. So each colour carries one tail length (Tail Waste Per Join x Number of Colour Changes) on top of its share, and the project total is two tails per join.
Frequently Asked Questions
Chart your pattern on graph paper and count the stitches of each colour. Divide each colour's stitch count by the total to get the percentage. For repeating patterns, you only need to count one repeat.
Yes, add 15-20% extra for colourwork. Stranded techniques (Fair Isle) use more yarn due to floats on the back. Intarsia uses more due to tail ends at colour changes.
Stranded colourwork (Fair Isle) typically produces a slightly tighter gauge than single-colour knitting because of the floats. Many knitters go up a needle size for the colourwork section. Always swatch in the colourwork pattern.
Related Calculators
Intarsia Yarn Calculator
Calculate yarn lengths for each colour block in intarsia colourwork.
Stripe Sequence Calculator
Calculate yarn needed per colour for striped patterns with custom sequences.
Fair Isle Yarn Calculator
Calculate yarn needed for each colour in a Fair Isle pattern based on percentage.
Gradient Calculator
Calculate yarn quantities for gradient or ombre colour transitions.
Colour Work Yarn Calculator
Calculate yarn needed per colour for Fair Isle and stranded colourwork from chart dimensions, gauge and yarn weight.
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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.