Weigh your leftover yarn without its container, bobbin, label or other packaging. Either remove these items or zero the scale with the empty container before adding the yarn. Enter the resulting net yarn mass in grams, along with the original ball’s labelled mass in grams and length in metres.
Enter the length your project requires and an additional allowance percentage. For example, 10% adds 10 metres to a 100-metre requirement. The default allowance is illustrative, not a universal recommendation. If your required length already includes your chosen allowance, enter 0%.
The signed balance shows whether the estimate meets the adjusted requirement: positive means a surplus, negative means a shortfall, and exactly zero means it just meets the requirement.
Cheryx’s leftover yarn guide describes obtaining metres per gram by dividing the original length by the original mass. Multiplying that ratio by the net remaining mass gives the estimate used here. The allowance and signed balance are direct percentage and subtraction calculations.
| Net yarn mass | Estimated length | Required length | Allowance | Adjusted requirement | Balance and interpretation |
|---|---|---|---|---|---|
| 35 g | 35 ÷ 100 × 240 = 84 m | 70 m | 10% = 7 m | 77 m | +7 m: estimated surplus |
| 30 g | 30 ÷ 100 × 240 = 72 m | 70 m | 10% = 7 m | 77 m | −5 m: estimated shortfall |
| 32 g | 32 ÷ 100 × 240 = 76.8 m | 64 m | 20% = 12.8 m | 76.8 m | 0 m: just meets the adjusted requirement |
| 0 g | 0 m | 70 m | 10% = 7 m | 77 m | −77 m: no yarn remains |
Use 0–100,000 g for net leftover mass, 0.01–100,000 g for label mass, 0.01–1,000,000 m for label length, 0–1,000,000 m for required length, and 0–100% for allowance. These are calculator input limits, not measurement accuracy claims. Enter only as much precision as your scale and label support.
Both mass entries are numerical gram counts whose units cancel in the mass ratio. All length entries must be in metres. Do not mix grams with ounces or metres with yards. A label mass of zero is invalid; unavailable results must not be interpreted as zero yarn.
Use the label for the actual yarn being weighed. Calculate different yarns separately rather than treating a mixed scrap pile as one yarn. The estimate assumes a constant length per gram; label rounding, scale resolution and differences in the yarn can affect it. The result does not guarantee that a project will be completed. It also does not account for whether the yarn is in one continuous piece.
Displayed lengths are rounded to two decimal places. A displayed balance of 0.00 m can hide a small surplus or shortfall; do not treat a near-zero result as a comfortable margin.
If yarn plus bobbin weighs 47 g and the empty bobbin weighs 12 g, enter 35 g as the net leftover mass: 47 − 12 = 35. With a 240 m per 100 g label, that estimates 84 m of yarn. Entering the gross 47 g would incorrectly estimate 112.8 m. A negative net mass means the weighing or tare measurement needs checking.
Draft production flag: no registered thumbnail asset was supplied. Create and register a 400 × 400 pixel WebP thumbnail, then add it as the first image block. Match neighboring thumbnails: a cheerful yellow five-point star mascot floating with hands and no separate legs or feet, on a white background, with navy, blue and teal yarn, scale and measuring graphics. Do not invent an asset ID.