What is a dye lot and why does it matter?

A dye lot is a batch of yarn dyed at the same time in the same dye bath. Even with precise recipes, there are always tiny colour variations between dye lots. These differences may be invisible when comparing single balls but become obvious as stripes or bands when knitted together. Always buy enough from the same dye lot for your entire project.

How can I tell if yarn is from the same dye lot?

Check the ball band for the dye lot number (sometimes labelled "lot" or "batch"). All balls with the same lot number were dyed together and should match perfectly. Some hand-dyed and undyed yarns may not have lot numbers; for hand-dyed yarn, buy enough at once from the same batch.

What if I cannot get enough from one dye lot?

If you must use two dye lots, alternate balls every 2 rows across the transition zone. This gradually blends the colours rather than creating a visible line. Start alternating about 5cm before the old lot runs out. This technique works well for most projects.

Do all yarns have dye lots?

Most dyed yarns have dye lots. Some brands (like Stylecraft Special DK) are labelled "no dye lot" meaning their colour matching is so consistent between batches that variations are negligible. Undyed natural yarns and some tonal/variegated yarns may also skip lot numbers. When in doubt, buy enough at once.

KnitCalcs

Yarn Lot Calculator — Same Dye Lot Planning

Calculate how many balls from the same dye lot you need to complete your project without colour variations.

Total Metres Needed

From your pattern or project calculator

Metres Per Ball

Check the ball band

Add extra for safety

Adds 10% extra for swatching and mistakes

Extra Percentage

10% is standard, 15% for colourwork

Price Per Ball (optional)

How We Calculate This

This calculator adds a safety margin to your yarn requirement and rounds up to whole balls to ensure you buy enough from a single dye lot.

The formula

Adjusted metres = Total metres needed x (1 + Extra %)

Balls needed = Adjusted metres / Metres per ball (rounded up)

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.