How to Calculate Unit Price
Sometimes the cheaper-looking product is not actually the better deal.
A small pack might have a lower price tag, but a larger pack may give you more for each dollar. Unit price helps you compare them fairly by showing the cost for one unit, such as one gram, one ounce, one liter, or one item.
The unit price formula
The basic formula is simple:
Unit price = total price / total quantity
Once two products use the same unit, the lower unit price is usually the better value.
Example: comparing rice by grams
Imagine you are comparing two bags of rice. One 500 g bag costs $3.50.
$3.50 / 500 g = $0.007 per gram
Another 1 kg bag costs $6.20. Since 1 kg is 1,000 g, the calculation is:
$6.20 / 1,000 g = $0.0062 per gram
Even though the 1 kg bag costs more at checkout, it is cheaper per gram. If you will use the rice before it expires and have space to store it, the bigger bag is the better value.
Example: comparing bottles by ounces
A 12 oz bottle costs $4.80, which works out to $0.40 per ounce. A 20 oz bottle costs $7.00, which works out to $0.35 per ounce.
The 20 oz bottle costs more upfront, but it gives you more product for each dollar.
When unit price helps most
Unit price is useful for drinks, shampoo, detergent, snacks, coffee, meat, supplements, pantry staples, and multipacks. It is especially helpful when:
- Package sizes are different
- One product is on sale
- One item comes in a multipack
- Brands use different units
- Bulk packs look cheaper but you are not sure
Common mistake: comparing only the shelf price
A $4 bottle is not automatically cheaper than a $6 bottle if the $6 bottle contains twice as much. Shelf price tells you what you pay today. Unit price tells you what you get for the money.
Use the calculator
To calculate unit price, divide the price by the amount you get. If products use different units, convert them to the same unit first.