Choose a common base
Compare mass with mass, volume with volume, or identical item counts. Convert both packs to the same base unit before dividing price by quantity.
Cheapest is not always best value
A lower unit price can be wasted if the product expires, cannot be stored or exceeds what the household will use.
Check what is actually included
Concentrates, drained weights, refills and bundles may not be directly comparable. Use the quantity that reflects the usable product.
Practical checklist
- Ignore promotional wording until the unit prices are calculated.
- Include membership fees only when relevant to the decision.