How is the per-unit price calculated?

Price ÷ size, separately for each package. A 500 g jar at 6.49 works out to 6.49 / 500 = 0.013 per gram. The calculator does the division for you and shows every row side by side, currency-formatted in your selected currency.

Is the cheapest per unit always the right buy?

Not always. A bigger pack is only the better deal if you actually use it before it spoils, and if you have room to store it. A smaller pack can be the smarter choice when waste is a real risk — the calculator answers "cheapest per unit", which is one signal of value, not the whole picture.

Can I compare a package measured in ounces against one in grams?

No — this calculator does not convert between units. Use the same unit label across all rows, or convert the sizes yourself first with a length, weight, or volume converter. Comparing 12 oz to 500 g without converting will give you a meaningless ratio.

What unit should I type in the Unit field?

Whatever the package is sold by — oz, g, ml, sheets, count, tea bags, eggs, square feet, anything that fits. The label is cosmetic; it appears next to each price so you can read the result as e.g. "0.50 / oz" without ambiguity. The math is the same no matter what you type.

How is this different from the discount, tip, or split-bill calculators?

Those three each work on a single bill: the discount calculator takes a percent off one price, the tip calculator adds a tip to one bill, and the split-bill calculator divides one bill among several people. Unit price comparison is the only one that compares per-unit cost across two or three different package sizes — apples to apples on a per-unit basis.

EVEEveryday Costs

Unit Price Comparison

Compare two or three differently-sized packages of the same product to see which is cheapest per unit. Enter the size and price of each, choose the unit you are pricing by (oz, g, ml, sheets, count, anything you like), and the calculator divides price by size for each row, highlights the lowest per-unit price, and shows how much cheaper it is than the most expensive option.

Currency

Unit

Package A — size

Package A — price

Package B — size

Package B — price

Package C — size (optional)(optional)

Package C — price (optional)(optional)

Try an example

Enter values above to see results

How It Works

Formula

p_i = \dfrac{\text{price}_i}{\text{size}_i}

\text{savings\%} = \left(1 - \dfrac{\min_i p_i}{\max_i p_i}\right) \times 100

Where

$p_i$: Per-unit price of package i
$\text{price}_i$: What package i costs
$\text{size}_i$: How many units package i contains

Enter the size and price of package A and package B. Optionally add a third package C if you have one. Type the unit you are pricing by — oz, g, ml, sheets, anything — into the Unit field. The calculator divides price by size for each row, highlights the lowest per-unit price as the hero, and shows how much cheaper it is than the most expensive option as a percentage.

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