Quantities
How many balls of yarn do I need?
Start with the yarn quantity in your pattern for the size you are making. Divide that length by the metres in one ball of the specified yarn, then round up. Do this separately for every colour.
A worked example
Suppose your pattern requires 1,200 metres of one colour and each ball contains 196 metres. 1,200 ÷ 196 = 6.122…, so buy 7 balls. Those balls contain 1,372 metres altogether. The extra 172 metres comes from buying whole balls; it is not a separate allowance you need to add again.
Use the length, not just the ball weight
A 100g ball does not contain a fixed number of metres. For example, Stylecraft lists Special Aran at 196m per 100g and Special DK at 295m per 100g. These are different yarns, not interchangeable recommendations. Read the label for the actual yarn your pattern specifies.
If your pattern lists balls instead
For the exact same yarn and ball size, the designer’s ball count is the starting point. If you need to enter it into the planner, multiply the count by the labelled metres per ball. This converts the stated purchase quantity; it does not discover the exact amount the project will use.
Before ordering
Check your selected pattern size, every colour quantity, the exact product and the ball size. A change of yarn may change the result even when the length looks sufficient. The planner calculates shopping quantities from your inputs; it does not check yarn suitability or guarantee that a garment will fit.
| Requirement | Whole balls | Purchased length |
|---|---|---|
| 196m | 1 | 196m |
| 197m | 2 | 392m |
| 600m | 4 | 784m |
| 1,200m | 7 | 1,372m |
Check before you move on
- Use the quantity for the selected pattern size
- Copy metres per individual ball from the label
- Round each colour separately
- Keep pack size separate from ball length
Try it with your own numbers.
Calculate whole balls or packs for every colour. Subtract your stash and add UK delivery.
Build my list ↗Common questions
Should I round to the nearest ball?
Round up to a whole ball. Rounding down can leave the entered requirement uncovered. If the requirement is exactly a whole number of balls, the calculator does not add another one.
Can this calculate yarn from a jumper size?
No. Use the pattern’s quantity for that size. Fit, stitch pattern and yarn choice cannot be inferred from a size label alone.
Sources and scope
Sources checked 29 September 2026. Label facts come from the linked references; worked purchase examples and arithmetic are our own illustrations.
Keep planning
- Calculate yarn separately for every colour
- Should I add an extra yarn allowance?
- Check your measuring and planning kit
These are planning methods, not physically tested crochet patterns. Read our method and editorial approach.