The Rothwell scale, or Rothwell system, or Rothwell method, applied to incontinence care products, is a scale that shows how absorbent a particular incontinence pad or adult diaper is, and how much liquid it can absorb and hold before it is likely to leak due to overfill.
The system provides a quick reference for assessing how much liquid can be held by a sheet, pad or diaper, and therefore how appropriate it will be for a particular individual in any given circumstance. The scale is based on the total absorbency test ISO 11948–1. The scale runs from 1 to 22, with 1 indicating the least liquid absorbed, measured in grams, and 22 the most liquid absorbed. The scale also applies a prefix to show what type of product is being referred to, with pads and sheets having an “I” prefix, and all in one diapers using a D prefix.
| Scale | Absorbency | Scale | Absorbency | ||
|---|---|---|---|---|---|
| I1 | 0g to 49g | D14 | 1300g to 1699g | ||
| I2 | 50g to 99g | D15 | 1700g to 2099g | ||
| I3 | 100g to 199g | D16 | 2100g to 2499g | ||
| I4 | 200g to 299g | D17 | 2500g to 2899g | ||
| I5 | 300g to 449g | D18 | 2900g to 3299g | ||
| I6 | 450g to 599g | D19 | 3300g to 3699g | ||
| I7 | 600g to 799g | D20 | 3700g to 4099g | ||
| I8 | 800g to 999g | D21 | 4100g to 4499g | ||
| I9 | 1000g to 1249g | D22 | 4500g to 4899g | ||
| I10 | 1250g to 1499g | ||||
| I11 | 1500g to 1799g | ||||
| I12 | 1800g to 2099g | ||||
| I13 | 2100g to 2499g | ||||
| I14 | 2500g to 2899g | ||||
| I15 | 2900g to 3299g |