Compare the pack, not just the price tag.

Two packs of the same everyday item can sit beside each other with very different price tags. The smaller number catches your eye first. It is easier to pay today—but it does not always buy the lower price for the amount inside.

The useful question is not only “Which pack costs less?” It is “What does each pack cost for the same quantity?”

Put both packs on the same scale

Start with the final price and the quantity written on the package. Then choose one common basis:

• For goods measured by weight, compare the price per 100 g or per kilogram.
• For liquids, compare the price per 100 mL or per litre.
• For counted items, compare the price per piece.

For a price per 100 g or 100 mL, divide the pack price by its quantity, then multiply by 100. For a price per piece, divide by the number of pieces.

In that example, the 750 g pack has the higher checkout price but the lower price per 100 g. The shelf price and the comparable price answer two different questions.

Check that the comparison is honest

Matching the unit is only part of the job. Before treating two numbers as comparable, check the product details around them.

Are they the same variant? Does one pack contain several smaller packs? Is the marked price already discounted? Are you reading the net quantity rather than the size of the container?

A neat calculation can still mislead when the products are not actually alike. “Per 100 g” helps compare quantity; it does not erase differences in ingredients, quality, convenience, or what your household will use.

Better value can still be the wrong buy

The lowest unit price is useful evidence, not an instruction.

A larger pack may cost less per unit and still be a poor choice if it strains today’s budget, will not fit at home, or may go unused. A smaller pack may cost more per unit and still be sensible when you need only a little, want to try something first, or need to keep the checkout total down.

This is why “cheapest” needs a full sentence. Cheapest per 100 g? Lowest amount to pay now? Lowest cost for the quantity you will actually use? Each can point to a different pack.

Keep the pack beside the price

A remembered price without its quantity is hard to reuse. “I paid ₱84 last time” becomes meaningful only when you can also recover the product, variant, pack size, store, and date.

Presylo keeps package details beside confirmed purchase prices and, when quantity and unit data are available, can normalize them for comparison. That capability is documented in Presylo’s dated 19 July 2026 product update.

When recording a repeat purchase, check the quantity and unit as carefully as the price. Next time, you will have more than a vague memory that one pack felt cheaper. You will have two purchases that can stand on the same scale.

Keep this

Receipt summary

Observed

A lower shelf price can belong to a pack that costs more for the same quantity.

Takeaway

Compare matching products on a common unit, then decide whether the larger outlay suits your budget and needs.

Try next

For one repeat purchase, record the exact pack size and calculate its price per 100 g, per litre, or per piece.

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