Unit Price Calculator AU
Compare two products by price per unit and instantly see which is the better value and by how much.
How it works
Enter the price and size (weight, volume or count) of two products using the same unit. The calculator divides each price by its size to get the price per unit, compares the two, and tells you which item is cheaper per unit and the percentage you save by choosing it.
Frequently asked questions
What is unit price?
Unit price is the cost of one unit of a product — such as the price per gram, per millilitre, per ounce or per item. It is found by dividing the total price by the quantity in the pack.
How do I calculate the unit price?
Divide the total price by the quantity. A 500 g item costing 3.00 has a unit price of 3.00 ÷ 500 = 0.006 per gram. Compare two items by putting both quantities in the same unit first.
Is the bigger package always cheaper per unit?
No. Larger packs are often — but not always — cheaper per unit. Promotions, multi-buys and ‘value’ small packs can flip the maths, which is exactly why it is worth checking the unit price.
How do I compare items sold in different units?
Convert both to the same unit before comparing. For example, change 1 kg to 1,000 g, or 1 litre to 1,000 ml, so both unit prices are measured the same way.
What is shrinkflation?
Shrinkflation is when a product’s pack size shrinks while the price stays the same, quietly raising the unit price. Comparing unit prices over time is the easiest way to spot it.
Does a lower unit price always mean better value?
It usually does for identical products, but consider quality, freshness and waste. A cheaper unit price is no saving if the larger quantity spoils before you can use it.
Unit Price Calculator
The unit price is what a product actually costs per gram, millilitre, ounce or item — the single most useful number for spotting the best value on a shelf. This calculator compares two products and tells you which is cheaper per unit and by how much, so the bigger pack or the “special offer” can be checked in seconds.
What is unit price?
Unit price is the total price divided by the quantity in the package. A 500 g jar at 3.00 has a unit price of 0.006 per gram; a 1 kg jar at 5.00 works out to 0.005 per gram. Even though the big jar costs more at the till, it is cheaper per gram — exactly the kind of comparison unit pricing makes obvious.
How to calculate unit price
Unit price = Total price ÷ Quantity
To compare two products fairly, put both quantities in the same unit (both in grams, both in millilitres, and so on), then compare the two unit prices. The lower number is the better value.
Worked example
| Item | Price | Size | Unit price |
|---|---|---|---|
| Item A | 3.00 | 500 g | 0.0060 / g |
| Item B | 5.00 | 1000 g | 0.0050 / g |
Item B is 16.7% cheaper per gram, even though it has the higher sticker price.
Smart price-comparison tips
- Always convert to the same unit before comparing — grams vs kilograms will mislead you.
- The bigger pack is not always cheaper per unit; retailers sometimes price small packs better on promotion.
- Factor in waste — a bulk buy is only a saving if you actually use it before it spoils.
- Watch for “shrinkflation”: same price, smaller pack means a higher unit price.
- Use the shelf-edge unit price where it is shown, and this tool where it is not.
Where unit pricing helps most
- Groceries — comparing brands, pack sizes and multi-buys.
- Household supplies — detergent, paper goods, pet food.
- Bulk and warehouse shopping — checking whether membership packs really save money.
- Online shopping — where shelf unit prices are rarely shown.
Results are estimates for general guidance in Australia and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.