Unit price calculator: which pack is really cheaper?
Put in the price and size of two packs. We'll work out the cost per 100 g, 100 mL or item, and tell you which one is better value.
Updated 27 September 2026 · By SnagList, Sydney
How unit pricing works
Unit price is the cost for a standard amount, like $0.90 per 100 g. It lets you compare a 500 g pack with a 1 kg pack, or a 6-pack with a 24-pack, without doing sums in the aisle.
The formula is simple: price ÷ size × 100 for grams or millilitres, or price ÷ number of items for things sold by count. The calculator converts kilograms and litres for you.
Why the bigger pack isn't always cheaper
- Specials: a half-price small pack often beats the full-price bulk pack.
- Waste: a cheaper unit price only helps if you use it all before it expires.
- Different products: compare like with like. A cheaper unit price on a lower-quality product may not be a saving.
Where to find unit prices
Australian supermarkets usually show the unit price in small print on the shelf label and online product pages. For online stores that don't, use this calculator.
Common questions
How do I calculate unit price?
Divide the price by the size, then multiply by the unit you want to compare. For example, $4.50 for 500 g is $4.50 ÷ 500 × 100 = $0.90 per 100 g.
Is the bigger pack always cheaper?
No. Specials on smaller packs often make them cheaper per 100 g than the bulk size. Always compare the unit price.
Can I compare grams with kilograms?
Yes. The calculator converts kg to g and L to mL for you. You can't compare weight with volume, though.
Where do I find unit prices in store?
Australian supermarkets usually print the unit price in small text on the shelf label, for example per 100 g, per kg or per litre.
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