Choose the target yourself
The stock tool is purchase arithmetic. It does not predict how many washes a bottle provides or how often an individual should shampoo. For the selected400ml cosmetics,it can round a user-chosen matching volume target to complete bottles.
A worked purchase example
If the chosen target is1000ml and200ml of the exact matching cosmetic is already held,the gap is800ml. Two400ml bottles add800ml and bring the recorded total to1000ml. This is not a consumption forecast,an expiry approval or a recommendation to own that amount.
Keep unlike stock separate
Do not subtract a different formula,another size or a medicine from the cosmetic target merely because all are called shampoo. A chosen whole-bottle count can be recorded for the selected medicine,but volume-to-treatment-course calculations are refused. No hair-length dose or automatic monthly demand is generated.
Check before ordering
The fields accept bounded nonnegative whole numbers and clear the target when the product or basis changes. Confirm actual labels,usable stock,expiry and seller limits. Unknown quantities remain unresolved rather than being treated as zero or converted into a treatment plan.
A concrete decision record
For a different example,choose1300ml of the exact Faith cosmetic and record100ml already held. The1200ml gap rounds to three400ml bottles. If1000ml were already held,the300ml gap would still require one400ml bottle and leave100ml above the chosen target. Neither example assigns a period of use.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent clinical/chemical/content/commerce review remain pending.
Boots Simple400ml selected redirect10375990/8219443 ↗
Faith In Nature400ml one-time manufacturer record ↗
Boots Nizoral2%w/w60ml10025089/2695103 ↗