Compare packs by price per kilogram, litre or item: how to convert to one base unit, a worked example, and what unit prices do not tell you.
Choose a common base
Compare mass with mass, volume with volume, or identical item counts, and convert both packs to the same unit before dividing price by quantity.
Worked example
500 g for 3.00 is 6.00 per kg, or 0.60 per 100 g. 750 g for 4.65 is 6.20 per kg. The smaller pack is about 3.2% cheaper per kilogram: 500 g bought at the larger pack’s rate would cost 3.10.
Check what is actually included
Concentrates, drained weights, refills and multipacks may not be directly comparable. Use the quantity of usable product.
Cheapest is not always best value
A lower unit price is wasted if the product expires or exceeds what the household will use.
Practical checklist
Ignore promotional wording until the unit prices are calculated.
Compare against the shelf-edge unit price, but check it uses the same unit.
Include membership fees only when relevant.
Babushka Picks
A short list for the next step
Start with the essential item, add the useful option when it improves the job, and treat the final choice as optional.
Divide each price by its total quantity in the same base unit, including all items in a multi-pack. A 500 g pack at 3 costs 6 per kg, while a 1 kg pack at 6.20 costs 6.20 per kg. The larger pack is not automatically cheaper.
Can I compare price per litre with price per kilogram?
Only when you know the product's relevant density and deliberately convert the quantities. The ordinary comparison modes keep mass, volume and item counts separate. Choose compatible units so that the displayed lower unit price represents a meaningful comparison between the products.
Does the lowest unit price always mean the best purchase?
No. The result compares quantity and price under the stated inputs. Consider how much you will use, storage, expiry, quality and your cash outlay. A discounted larger pack can waste money if much of it is discarded before use. Check usable stock too. Check usable stock too.
Calculation/content reviewed 4 October 2026. Source: Babushka Market’s displayed formulas, units and labelled editable assumptions. How the estimates work
